Pregnancy Test: From 1 Different Sources
any of several methods used to demonstrate whether or not a woman is pregnant. Most pregnancy tests are based on the detection of a hormone, *human chorionic gonadotrophin (hCG), in the urine. The sample of urine is mixed with serum containing antibodies to hCG and marker particles (sheep red cells or latex particles) coated with hCG. In the absence of pregnancy, the antibodies will cause *agglutination of the marker particles. If the urine is from a pregnant woman, the antibodies will be absorbed and no agglutination will occur. These tests may be positive for pregnancy as early as 30 days after the date of the last normal period and are 98% accurate. Newer tests using *monoclonal antibodies (beta hCG) are more easily interpreted. When carried out on serum rather than urine, these tests give even earlier positive results.
The principal reproductive androgen of males, largely responsible for sexual maturation, some libido, and a range of metabolic reactions that, while supplying short-term strengths, creates a long-term fragility and brittleness if not in balance with less garish but more sustainable metabolic buffers. It is secreted by the Leydig cells of the testes, as well as smaller amounts in the adrenal cortices of both sexes. It is made under the direction of LH from the pituitary, and, if oversecreted, can be inhibited by sperm-producing cells, diminished pituitary support, and a rise in blood levels of its waste-product, stored in adipose tissues...estradiol... testosterone
A skin test to ?nd out if a person is immune to TUBERCULOSIS. TUBERCULIN (a preparation derived from the TUBERCLE bacillus) is injected via punctures in the skin of the forearm, using a spring-loaded gunlike instrument with six very short needles set in circular form. A positive test is indicated by a red raised reaction of the skin: this means that the subject is immune. If the result is negative, the subject can be given BCG VACCINE.... heaf test
An ectopic pregnancy most commonly develops in one of the FALLOPIAN TUBES. Occasionally it may occur in one of the OVARIES, and rarely in the uterine cervix or the abdominal cavity. Around one in 200 pregnant women have an ectopic gestation. As pregnancy proceeds, surrounding tissues may be damaged and, if serious bleeding happens, the woman may present as an ‘abdominal emergency’. A life-threatening condition, this needs urgent surgery. Most women recover satisfactorily and can have further pregnancies despite the removal of one Fallopian tube as a result of the ectopic gestation. Death is unusual. This disorder of pregnancy may occur because infection or a previous abdominal injury or operation may have damaged the normal descent of an ovum from the ovary to the womb. The ?rst symptoms usually appear during the ?rst two months of pregnancy, perhaps before the woman realises she is pregnant. Severe lower abdominal pain and vaginal bleeding are common presenting symptoms. Ultrasound can be used to diagnose the condition and laparoscopy can be used to remove the products of conception. (See PREGNANCY AND LABOUR.)... ectopic pregnancy
A test for TUBERCULOSIS. It consists in injecting into the super?cial layers of the skin (i.e. intradermally) a very small quantity of old TUBERCULIN which contains a protein ANTIGEN to TB. A positive reaction of the skin – swelling and redness – shows that the person so reacting has been infected at some time in the past with Mycobacterium tuberculosis. However, it does not mean that such a person is suffering from active tuberculosis.... mantoux test
This is used to identify possible substances that may be causing a patient’s ALLERGY. Small amounts of di?erent substances are placed on the skin – usually of the back or arm. If the patient is allergic then a red ?are and swelling will appear, usually within about 15 minutes. Sometimes the reaction may take longer – up to three days – to develop.... patch test
A psychological test (see PSYCHOLOGY) for investigating personality and disorders of personality. Also called the ‘ink blot test’, it is now rarely used. It was devised by a Swiss psychiatrist, Hermann Rorschach (1884–1922), who determined individuals’ reactions to a series of symmetrical ink-blots, ten in number and standardised by him.... rorschach test
Every man has two testicles or testes which are the sexual glands. In the fetus, they develop in the abdomen, but before birth they descend into a fold or pouch of skin known as the SCROTUM. Each testicle consists of up to 1,000 minute tubes lined by cells from which the spermatozoa (see SPERMATOZOON) are formed. Around 4·5 million spermatozoa are produced per gram of testicle per day. These tubes communicate with one another near the centre of the testicle, and are connected by a much coiled tube, the EPIDIDYMIS, with the ductus, or VAS DEFERENS, which enters the abdomen and passes on to the base of the bladder. This duct, after joining a reservoir known as the seminal vesicle, opens, close to the duct from the other side of the body, into the URETHRA where it passes through the PROSTATE GLAND. Owing to the convolutions of these ducts leading from the testicles to the urethra, and their indirect route, the passage from testicle to urethra is over 6 metres (20 feet) in length. In addition to producing spermotozoa, the testicle also forms the hormone TESTOSTERONE which is responsible for the development of male characteristics.... testicle
Also known as ECTOPIC PREGNANCY. Implantation of the EMBRYO in one of the FALLOPIAN TUBES, rather than in the lining of the UTERUS. The patient usually complains of pain between six and ten weeks’ gestation and, if the Fallopian tube is not removed, there may be rupture with potentially life-threatening haemorrhage.... tubal pregnancy
Removal of venous, capillary or arterial blood for haematological, microbiological or biochemical laboratory investigations.... blood test
A test for vestibular function (see EAR). It is performed by irrigating the external auditory meatus of the ear with alternate cold and hot water. This usually stimulates the vestibular apparatus, causing nystagmus (see DIABETES MELLITUS – Diabetic eye disease). If the vestibular apparatus is affected by disease, the response may be absent or reduced.... caloric test
A sensitive test that detects ANTIBODIES to the body’s red cells (see ERYTHROCYTE). There are two methods: one – the direct method – identi?es those antibodies that are bound to the cells; the other, indirect, method identi?es those circulating unattached in the serum.... coomb’s test
Skin test used to determine the immune s tatus to scarlet fever.... dick test
A way of assessing the body’s e?ciency at metabolising GLUCOSE. The test is used in the diagnosis of DIABETES MELLITUS. The patient is starved for up to 16 hours, after which he or she is fed glucose by mouth. The concentrations of glucose in the blood and urine are then measured at half-hour intervals over a period of two hours.... glucose-tolerance test
A standardised procedure of mental assessment to determine an individual’s intellectual ability. The result is produced as a score termed the INTELLIGENCE QUOTIENT (IQ). The Wechsler Adult Intelligence Scale (WAIS) and one for children, the Wechsler Intelligence Scale for Children (WICS), are commonly used, as is the Stanford-Binet Scale. Assessments are made for educational purposes and to help in the diagnoses of people with possible mental retardation or intellectual deterioration.... intelligence test
The characteristic histological test used for the diagnosis of SARCOIDOSIS. The test involves an intradermal injection of sarcoid SPLEEN tissue. If positive, non-caseating granulomata (see GRANULOMA) are seen at the injection site in 4– 6 weeks. A positive test is highly speci?c for sarcoid, but if negative, this would not be excluded.... kveim test
See CERVICAL SMEAR.... papanicolaou test
See EMBRYO TRANSFER.... test-tube baby
The screening of apparently healthy people to identify those who may have treatable diseases. Cervical smears are done when screening women to detect if they have cancer or precancer of the neck of the womb (cervix). Newborn babies are screened for hip dislocation. Screening tests are not designed to diagnose individual persons, but rather to divide a population into a large number at low risk and a small number at high risk of a condition. This allows clinicians to concentrate on a sub-section of the population. All screening tests produce false negative and false positive results, a problem often misunderstood by those at the receiving end. Factors to be assessed when planning screening procedures include the severity, frequency and distribution of the disease, and the availability and e?ectiveness of treatment. Convenience, safety, sensitivity and cost should also be assessed. In the United Kingdom the government has supported the extension of screening procedures for breast cancer, cervical cancer, hypertension and diabetes. (See PREVENTIVE MEDICINE.)... screening test
Most vision tests examine a person’s sharpness of VISION (visual acuity) and often of the ?eld of vision (see VISION, FIELD OF). Refraction tests assess whether a person has an error that can be corrected with glasses such as ASTIGMATISM, HYPERMETROPIA or MYOPIA. Visual acuity is tested using a Snellen chart when the patient tries to read letters of di?ering standard sizes from 6 metres away. The optician will prescribe lenses to correct any defects detected by vision tests.... vision tests
A testis that is drawn up.... testis, retractile
A test for gauging the e?ciency of the balancing mechanism (the vestibular apparatus) by applying hot or cold air or water to the external ear.... barany’s test
A medico-legal defence for a clinician accused of failing to provide an acceptable standard of care for one of his or her quali?cation and experience. The defence is that a responsible body of medical practitioners would have taken the same action, even though others would have acted di?erently. The precise size of a ‘responsible body’ has not been de?ned. The test has been modi?ed following a case referred to as Bolitho, in which it was held that the Bolam defence failed if it could be shown that the actions relied upon, although shown to be carried out by some responsible doctors, were nonetheless illogical.... bolam test
In surveys, studying the process of interpretation of questions and the formation and reporting of responses by respondents to learn how to make the questions more accurately obtain the data the questionnaire is seeking.... cognitive testing
See ECTOPIC PREGNANCY.... extrauterine pregnancy
See GENETIC SCREENING.... gene testing
A test for colour vision, introduced by a Japanese doctor, comprising several plates with round dots of di?erent colours and sizes. It is also the name of a type of blood test for SYPHILIS.... ishihara’s test
Women need to be careful both with what they eat and drink during pregnancy. Even if tea is generally recommended as an everyday beverage, most teas shouldn’t be drunk during pregnancy. Find out which teas you should and shouldn’t drink when you’re pregnant.
Careful with teas for pregnancy
There are various reasons why pregnant women should be careful with the type of tea they drink. Many are related to the caffeine content some tea varieties might have. Drinking tea with caffeine content might lead to birth defects or even unwanted miscarriages.
Also, other tea varieties can lead to uterine contractions, or have properties that involve regulating menstruation. These can also lead to miscarriages.
That doesn’t mean that, during pregnancy, women should completely stay away from teas. They just have to know what type of tea they can drink.
Teas you can drink for pregnancy
Rooibos tea is often recommended to pregnant women, as it doesn’t contain caffeine at all. It contains antioxidants, as well as a low level of tannins. Thanks to this, they are less likely to interfere with iron absorption and, therefore, cause anemia during and after pregnancy. It also helps with indigestion and may relieve nausea.
Pregnant women can drink ginger tea or mint tea, which help with morning sickness, or chamomile tea to prevent insomnia. Also, nettle tea can be drunk during the second and third trimester of the pregnancy (not the first) only if it’s made from nettle leaves and not from the root.
Raspberry leaf tea has many benefits related to pregnancy. First of all, if a woman wants to get pregnant, this tea will increase fertility, as well as strengthen the uterine wall and relax the muscle in the uterus. During pregnancy, it helps with leg cramps, morning sickness and diarrhea. Also, drinking this tea may lead to less artificial ruptures in the membranes, which lowers the chances of needing a caesarean delivery, as well as needing forceps or vacuum birth.
Teas you shouldn’t drink for pregnancy
Even if teas are usually considered to be good for our health, this isn’t the case. Women should be careful not to drink various types of tea for pregnancy.
It is considered best for pregnant women not to drink teas that contain caffeine. Teas made from the Camellia sinensis plant (green tea, black tea, white tea, oolong tea) contain caffeine, so it is best to avoid them. Small amounts may be acceptable, however it can still be risky, as they might still lead to birth defects or miscarriages.
Pregnant women should also be careful with herbal teas. The varieties they shouldn’t drink include devil’s claw, ephedra, fenugreek, gentian, ginseng, hawthorne, motherwort, red raspberry leaf, senna, shepherd’s purse, St. John’s wort, or yarrow.
Teas for labor
Partridge tea is recommended for pregnant women who are due to give birth. It is recommended to be drunk during the last 2-3 weeks of pregnancy.
Partridge tea helps with relieving congestions of the uterus and ovaries. It can also be used as an antiseptic to treat vaginal infections. Plus, when it is combined with raspberry leaves, it can help even more during the last two weeks of pregnancy.
Pregnant women should be careful even when it comes to the type of tea they drink. Some might be harmful, while others may help them a lot both during and after pregnancy. If you want to get pregnant, make sure you remember the accepted teas for pregnancy.... drinking tea for pregnancy
See under TESTICLE, DISEASES OF.... maldescended testis
The determination of eligibility for a publicly financed programme on the basis of an applicant’s income and assets (means).... means test
A test for MONONUCLEOSIS which is based upon the fact that patients with this disease develop ANTIBODIES which agglutinate sheep red blood cells.... paul-bunnell test
A test for INFERTILITY. A specimen of cervical mucus, taken up to 24 hours after coitus (during the post-ovulatory phase of the menstrual cycle), is examined microscopically to assess the motility of the sperms. If motility is above a certain level, then sperms and mucus are not interacting abnormally – thus eliminating one cause of sterility.... post-coital test
Pregnancy The time when a woman carries a developing baby in her UTERUS. For the ?rst 12 weeks (the ?rst trimester) the baby is known as an EMBRYO, after which it is referred to as the FETUS.
Pregnancy lasts about 280 days and is calculated from the ?rst day of the last menstrual period – see MENSTRUATION. Pregnancy-testing kits rely on the presence of the hormone beta HUMAN CHORIONIC GONADOTROPHIN (b HCG) which is excreted in the woman’s urine as early as 30 days from the last menstrual period. The estimated date of delivery can be accurately estimated from the size of the developing fetus measured by ULTRASOUND (see also below) between seven and 24 weeks. ‘Term’ refers to the time that the baby is due; this can range from 38 weeks to 41 completed weeks.
Physical changes occur in early pregnancy – periods stop and the abdomen enlarges. The breasts swell, with the veins becoming prominent and the nipples darkening. About two in three women will have nausea with a few experiencing such severe vomiting as to require hospital admission for rehydration.
Antenatal care The aim of antenatal care is to ensure a safe outcome for both mother and child; it is provided by midwives (see MIDWIFE) and doctors. Formal antenatal care began in Edinburgh in the 1930s with the recognition that all aspects of pregnancy – normal and abnormal – warranted surveillance. Cooperation between general practitioners, midwives and obstetricians is now established, with pregnancies that are likely to progress normally being cared for in the community and only those needing special intervention being cared for in a hospital setting.
The initial visit (or booking) in the ?rst half of pregnancy will record the history of past events and the results of tests, with the aim of categorising the patients into normal or not. Screening tests including blood checks and ultrasound scans are a routine part of antenatal care. The ?rst ultrasound scan is done at about 11 weeks to date the pregnancy, with a further one done at 20 weeks – the anomaly scan – to assess the baby’s structure. Some obstetric units will check the growth of the baby with one further scan later in the pregnancy or, in the case of twin pregnancies (see below), many scans throughout. The routine blood tests include checks for ANAEMIA, DIABETES MELLITUS, sickle-cell disease and THALASSAEMIA, as well as for the blood group. Evidence of past infections is also looked for; tests for RUBELLA (German measles) and SYPHILIS are routine, whereas tests for human immunode?ciency virus (see AIDS/ HIV below) and HEPATITIS are being o?ered as optional, although there is compelling evidence that knowledge of the mother’s infection status is bene?cial to the baby.
Traditional antenatal care consists of regular appointments, initially every four weeks until 34 weeks, then fortnightly or weekly. At each visit the mother’s weight, urine and blood pressure are checked, and assessment of fetal growth and position is done by palpating the uterus. Around two-thirds of pregnancies and labours are normal: in the remainder, doctors and midwives need to increase the frequency of surveillance so as to prevent or deal with maternal and fetal problems.
Common complications of pregnancy
Some of the more common complications of pregnancy are listed below.
As well as early detection of medical complications, antenatal visits aim to be supportive and include emotional and educational care. Women with uncomplicated pregnancies are increasingly being managed by midwives and general practitioners in the community and only coming to the hospital doctors should they develop a problem. A small number will opt for a home delivery, but facilities for providing such a service are not always available in the UK.
Women requiring more intensive surveillance have their management targeted to the speci?c problems encountered. Cardiologists will see mothers-to-be with heart conditions, and those at risk of diabetes are cared for in designated clinics with specialist sta?. Those women needing more frequent surveillance than standard antenatal care can be looked after in maternity day centres. These typically include women with mildly raised blood pressure or those with small babies. Fetal medicine units have specialists who are highly skilled in ultrasound scanning and specialise in the diagnosis and management of abnormal babies still in the uterus. ECTOPIC PREGNANCY Chronic abdominal discomfort early in pregnancy may be caused by unruptured ectopic pregnancy, when, rarely, the fertilised OVUM starts developing in the Fallopian tube (see FALLOPIAN TUBES) instead of the uterus. The patient needs hospital treatment and LAPAROSCOPY. A ruptured ectopic pregnancy causes acute abdominal symptoms and collapse, and the woman will require urgent abdominal surgery. URINARY TRACT INFECTIONS These affect around 2 per cent of pregnant women and are detected by a laboratory test of a mid-stream specimen of urine. In pregnancy, symptoms of these infections do not necessarily resemble those experienced by non-pregnant women. As they can cause uterine irritability and possible premature labour (see below), it is important to ?nd and treat them appropriately. ANAEMIA is more prevalent in patients who are vegetarian or on a poor diet. Iron supplements are usually given to women who have low concentrations of HAEMOGLOBIN in their blood (less than 10.5 g/dl) or who are at risk of becoming low in iron, from bleeding, twin pregnancies and those with placenta previa (see below). ANTEPARTUM HAEMORRHAGE Early in pregnancy, vaginal bleedings may be due to a spontaneous or an incomplete therapeutic ABORTION. Bleeding from the genital tract between 24 completed weeks of pregnancy and the start of labour is called antepartum haemorrhage. The most common site is where the PLACENTA is attached to the wall of the uterus. If the placenta separates before delivery, bleeding occurs in the exposed ‘bed’. When the placenta is positioned in the upper part of the uterus it is called an abruption. PLACENTA PRAEVIA is sited in the lower part and blocks or partly blocks the cervix (neck of the womb); it can be identi?ed at about the 34th week. Ten per cent of episodes of antepartum bleeding are caused by placenta previa, and it may be associated with bleeding at delivery. This potentially serious complication is diagnosed by ultrasound scanning and may require a caesarean section (see below) at delivery. INCREASED BLOOD PRESSURE, associated with protein in the urine and swelling of the limbs, is part of a condition known as PRE-ECLAMPSIA. This occurs in the second half of pregnancy in about 1 in 10 women expecting their ?rst baby, and is mostly very mild and of no consequence to the pregnancy. However, some women can develop extremely high blood pressures which can adversely affect the fetus and cause epileptic-type seizures and bleeding disorders in the mother. This serious condition is called ECLAMPSIA. For this reason a pregnant woman with raised blood pressure or PROTEIN in her urine is carefully evaluated with blood tests, often in the maternity day assessment unit. The condition can be stopped by delivery of the baby, and this will be done if the mother’s or the fetus’s life is in danger. If the condition is milder, and the baby not mature enough for a safe delivery, then drugs can be used to control the blood pressure. MISCARRIAGE Also called spontaneous abortion, miscarriage is the loss of the fetus. There are several types:
threatened miscarriage is one in which some vaginal bleeding occurs, the uterus is enlarged, but the cervix remains closed and pregnancy usually proceeds.
inevitable miscarriage usually occurs before the 16th week and is typi?ed by extensive blood loss through an opened cervix and cramp-like abdominal pain; some products of conception are lost but the developing placental area (decidua) is retained and an operation may be necessary to clear the womb.
missed miscarriages, in which the embryo dies and is absorbed, but the decidua (placental area of uterine wall) remains and may cause abdominal discomfort and discharge of old blood.
THERAPEUTIC ABORTION is performed on more than 170,000 women annually in England and Wales. Sometimes the woman may not have arranged the procedure through the usual health-care channels, so that a doctor may see a patient with vaginal bleeding, abdominal discomfort or pain, and open cervix – symptoms which suggest that the decidua and a blood clot have been retained; these retained products will need to be removed by curettage.
Septic abortions are now much less common in Britain than before the Abortion Act (1967) permitted abortion in speci?ed circumstances. The cause is the passage of infective organisms from the vagina into the uterus, with Escherichia coli and Streptococcus faecalis the most common pathogenic agents. The woman has abdominal pain, heavy bleeding, usually fever and sometimes she is in shock. The cause is usually an incomplete abortion or one induced in unsterile circumstances. Antibiotics and curettage are the treatment. INTRAUTERINE GROWTH RETARDATION describes a slowing of the baby’s growth. This can be diagnosed by ultrasound scanning, although there is a considerable margin of error in estimates of fetal weight. Trends in growth are favoured over one-o? scan results alone. GESTATIONAL DIABETES is a condition that is more common in women who are overweight or have a family member with diabetes. If high concentrations of blood sugar are found, e?orts are made to correct it as the babies can become very fat (macrosomia), making delivery more di?cult. A low-sugar diet is usually enough to control the blood concentration of sugars; however some women need small doses of INSULIN to achieve control. FETAL ABNORMALITIES can be detected before birth using ultrasound. Some of these defects are obvious, such as the absence of kidneys, a condition incompatible with life outside the womb. These women can be o?ered a termination of their pregnancy. However, more commonly, the pattern of problems can only hint at an abnormality and closer examination is needed, particularly in the diagnosis of chromosomal deformities such as DOWN’S (DOWN) SYNDROME (trisomy 21 or presence of three 21 chromosomes instead of two).
Chromosomal abnormalities can be de?nitively diagnosed only by cell sampling such as amniocentesis (obtaining amniotic ?uid – see AMNION – from around the baby) done at 15 weeks onwards, and chorionic villus sampling (sampling a small part of the placenta) – another technique which can be done from 12 weeks onwards. Both have a small risk of miscarriage associated with them; consequently, they are con?ned to women at higher risk of having an abnormal fetus.
Biochemical markers present in the pregnant woman’s blood at di?erent stages of pregnancy may have undergone changes in those carrying an abnormal fetus. The ?rst such marker to be routinely used was a high concentration of alpha-fetol protein in babies with SPINA BIFIDA (defects in the covering of the spinal cord). Fuller research has identi?ed a range of diagnostic markers which are useful, and, in conjunction with other factors such as age, ethnic group and ultrasound ?ndings, can provide a predictive guide to the obstetrician – in consultation with the woman – as to whether or not to proceed to an invasive test. These tests include pregnancy-associated plasma protein assessed from a blood sample taken at 12 weeks and four blood tests at 15–22 weeks – alphafetol protein, beta human chorionic gonadotrophin, unconjugated oestriol and inhibin A. Ultrasound itself can reveal physical ?ndings in the fetus, which can be more common in certain abnormalities. Swelling in the neck region of an embryo in early pregnancy (increased nuchal thickness) has good predictive value on its own, although its accuracy is improved in combination with the biochemical markers. The e?ectiveness of prenatal diagnosis is rapidly evolving, the aim being to make the diagnosis as early in the pregnancy as possible to help the parents make more informed choices. MULTIPLE PREGNANCIES In the UK, one in 95 deliveries is of twins, while the prevalence of triplets is one in 10,000 and quadruplets around one in 500,000. Racial variations occur, with African women having a prevalence rate of one in 30 deliveries for twins and Japanese women a much lower rate than the UK ?gure. Multiple pregnancies occur more often in older women, and in the UK the prevalence of fertility treatments, many of these being given to older women, has raised the incidence. There is now an o?cial limit of three eggs being transferred to a woman undergoing ASSISTED CONCEPTION (gamete intrafallopian transfer, or GIFT).
Multiple pregnancies are now usually diagnosed as a result of routine ultrasound scans between 16 and 20 weeks of pregnancy. The increased size of the uterus results in the mother having more or worse pregnancy-related conditions such as nausea, abdominal discomfort, backache and varicose veins. Some congenital abnormalities in the fetus occur more frequently in twins: NEURAL TUBE defects, abnormalities of the heart and the incidence of TURNER’S SYNDROME and KLINEFELTER’S SYNDROME are examples. Such abnormalities may be detected by ultrasound scans or amniocentesis. High maternal blood pressure and anaemia are commoner in women with multiple pregnancies (see above).
The growth rates of multiple fetuses vary, but the di?erence between them and single fetuses are not that great until the later stages of pregnancy. Preterm labour is commoner in multiple pregnancies: the median length of pregnancy is 40 weeks for singletons, 37 for twins and 33 for triplets. Low birth-weights are usually the result of early delivery rather than abnormalities in growth rates. Women with multiple pregnancies require more frequent and vigilant antenatal assessments, with their carers being alert to the signs of preterm labour occurring. CEPHALOPELVIC DISPROPORTION Disparity between the size of the fetus and the mother’s pelvis is not common in the UK but is a signi?cant problem in the developing world. Disparity is classi?ed as absolute, when there is no possibility of delivery, and relative, when the baby is large but delivery (usually after a dif?cult labour) is possible. Causes of absolute disparity include: a large baby – heavier than 5 kg at birth; fetal HYDROCEPHALUS; and an abnormal maternal pelvis. The latter may be congenital, the result of trauma or a contraction in pelvic size because of OSTEOMALACIA early in life. Disproportion should be suspected if in late pregnancy the fetal head has not ‘engaged’ in the pelvis. Sometimes a closely supervised ‘trial of labour’ may result in a successful, if prolonged, delivery. Otherwise a caesarean section (see below) is necessary. UNUSUAL POSITIONS AND PRESENTATIONS OF THE BABY In most pregnant women the baby ?ts into the maternal pelvis head-?rst in what is called the occipito-anterior position, with the baby’s face pointing towards the back of the pelvis. Sometimes, however, the head may face the other way, or enter the pelvis transversely – or, rarely, the baby’s neck is ?exed backwards with the brow or face presenting to the neck of the womb. Some malpositions will correct naturally; others can be manipulated abdominally during pregnancy to a better position. If, however, the mother starts labour with the baby’s head badly positioned or with the buttocks instead of the head presenting (breech position), the labour will usually be longer and more di?cult and may require intervention using special obstetric forceps to assist in extracting the baby. If progress is poor and the fetus distressed, caesarean section may be necessary. HIV INFECTION Pregnant women who are HIV positive (see HIV; AIDS/HIV) should be taking antiviral drugs in the ?nal four to ?ve months of pregnancy, so as to reduce the risk of infecting the baby in utero and during birth by around 50 per cent. Additional antiviral treatment is given before delivery; the infection risk to the baby can be further reduced – by about 40 per cent – if delivery is by caesarean section. The mother may prefer to have the baby normally, in which case great care should be taken not to damage the baby’s skin during delivery. The infection risk to the baby is even further reduced if it is not breast fed. If all preventive precautions are taken, the overall risk of the infant becoming infected is cut to under 5 per cent.
Premature birth This is a birth that takes place before the end of the normal period of gestation, usually before 37 weeks. In practice, however, it is de?ned as a birth that takes place when the baby weighs less than 2·5 kilograms (5••• pounds). Between 5 and 10 per cent of babies are born prematurely, and in around 40 per cent of premature births the cause is unknown. Pre-eclampsia is the most common known cause; others include hypertension, chronic kidney disease, heart disease and diabetes mellitus. Multiple pregnancy is another cause. In the vast majority of cases the aim of management is to prolong the pregnancy and so improve the outlook for the unborn child. This consists essentially of rest in bed and sedation, but there are now several drugs, such as RITODRINE, that may be used to suppress the activity of the uterus and so help to delay premature labour. Prematurity was once a prime cause of infant mortality but modern medical care has greatly improved survival rates in developing countries.
Labour Also known by the traditional terms parturition, childbirth or delivery, this is the process by which the baby and subsequently the placenta are expelled from the mother’s body. The onset of labour is often preceded by a ‘show’ – the loss of the mucus and blood plug from the cervix, or neck of the womb; this passes down the vagina to the exterior. The time before the beginning of labour is called the ‘latent phase’ and characteristically lasts 24 hours or more in a ?rst pregnancy. Labour itself is de?ned by regular, painful contractions which cause dilation of the neck of the womb and descent of the fetal head. ‘Breaking of the waters’ is the loss of amniotic ?uid vaginally and can occur any time in the delivery process.
Labour itself is divided into three stages: the ?rst is from the onset of labour to full (10 cm) dilation of the neck of the womb. This stage varies in length, ideally taking no more than one hour per centimetre of dilation. Progress is monitored by regular vaginal examinations, usually every four hours. Fetal well-being is observed by intermittent or continuous monitoring of the fetal heart rate in relation to the timing and frequency of the contractions. The print-out is called a cardiotocograph. Abnormalities of the fetal heart rate may suggest fetal distress and may warrant intervention. In women having their ?rst baby (primigravidae), the common cause of a slow labour is uncoordinated contractions which can be overcome by giving either of the drugs PROSTAGLANDIN or OXYTOCIN, which provoke contractions of the uterine muscle, by an intravenous drip. Labours which progress slowly or not at all may be due to abnormal positioning of the fetus or too large a fetus, when prostaglandin or oxytocin is used much more cautiously.
The second stage of labour is from full cervical dilation to the delivery of the baby. At this stage the mother often experiences an irresistible urge to push the baby out, and a combination of strong coordinated uterine contractions and maternal e?ort gradually moves the baby down the birth canal. This stage usually lasts under an hour but can take longer. Delay, exhaustion of the mother or distress of the fetus may necessitate intervention by the midwife or doctor. This may mean enlarging the vaginal opening with an EPISIOTOMY (cutting of the perineal outlet – see below) or assisting the delivery with specially designed obstetric forceps or a vacuum extractor (ventouse). If the cervix is not completely dilated or open and the head not descended, then an emergency caesarean section may need to be done to deliver the baby. This procedure involves delivering the baby and placenta through an incision in the mother’s abdomen. It is sometimes necessary to deliver by planned or elective caesarean section: for example, if the placenta is low in the uterus – called placenta praevia – making a vaginal delivery dangerous.
The third stage occurs when the placenta (or afterbirth) is delivered, which is usually about 10–20 minutes after the baby. An injection of ergometrine and oxytocin is often given to women to prevent bleeding.
Pain relief in labour varies according to the mother’s needs. For uncomplicated labours, massage, reassurance by a birth attendant, and a warm bath and mobilisation may be enough for some women. However, some labours are painful, particularly if the woman is tired or anxious or is having her ?rst baby. In these cases other forms of analgesia are available, ranging from inhalation of NITROUS OXIDE GAS, injection of PETHIDINE HYDROCHLORIDE or similar narcotic, and regional local anaesthetic (see ANAESTHESIA).
Once a woman has delivered, care continues to ensure her and the baby’s safety. The midwives are involved in checking that the uterus returns to its normal size and that there is no infection or heavy bleeding, as well as caring for stitches if needed. The normal blood loss after birth is called lochia and generally is light, lasting up to six weeks. Midwives o?er support with breast feeding and care of the infant and will visit the parents at home routinely for up to two weeks.
Some complications of labour All operative deliveries in the UK are now done in hospitals, and are performed if a spontaneous birth is expected to pose a bigger risk to the mother or her child than a specialist-assisted one. Operative deliveries include caesarean section, forceps-assisted deliveries and those in which vacuum extraction (ventouse) is used. CAESAREAN SECTION Absolute indications for this procedure, which is used to deliver over 15 per cent of babies in Britain, are cephalopelvic disproportion and extensive placenta praevia, both discussed above. Otherwise the decision to undertake caesarean section depends on the clinical judgement of the specialist and the views of the mother. The rise in the proportion of this type of intervention (from 5 per cent in the 1930s to its present level of over 23 per cent
P
of the 600,000 or so annual deliveries in England) has been put down to defensive medicine
– namely, the doctor’s fear of litigation (initiated often because the parents believe that the baby’s health has suffered because the mother had an avoidably di?cult ‘natural’ labour). In Britain, over 60 per cent of women who have had a caesarean section try a vaginal delivery in a succeeding pregnancy, with about two-thirds of these being successful. Indications for the operation include:
absolute and relative cephalopelvic disproportion.
placenta previa.
fetal distress.
prolapsed umbilical cord – this endangers the viability of the fetus because the vital supply of oxygen and nutrients is interrupted.
malpresentation of the fetus such as breech or transverse lie in the womb.
unsatisfactory previous pregnancies or deliveries.
a request from the mother.
Caesarean sections are usually performed using regional block anaesthesia induced by a spinal or epidural injection. This results in loss of feeling in the lower part of the body; the mother is conscious and the baby not exposed to potential risks from volatile anaesthetic gases inhaled by the mother during general anaesthesia. Post-operative complications are higher with general anaesthesia, but maternal anxiety and the likelihood that the operation might be complicated and di?cult are indications for using it. A general anaesthetic may also be required for an acute obstetric emergency. At operation the mother’s lower abdomen is opened and then her uterus opened slowly with a transverse incision and the baby carefully extracted. A transverse incision is used in preference to the traditional vertical one as it enables the woman to have a vaginal delivery in any future pregnancy with a much smaller risk of uterine rupture. Women are usually allowed to get up within 24 hours and are discharged after four or ?ve days. FORCEPS AND VENTOUSE DELIVERIES Obstetric forceps are made in several forms, but all are basically a pair of curved blades shaped so that they can obtain a purchase on the baby’s head, thus enabling the operator to apply traction and (usually) speed up delivery. (Sometimes they are used to slow down progress of the head.) A ventouse or vacuum extractor comprises an egg-cup-shaped metal or plastic head, ranging from 40 to 60 mm in diameter with a hollow tube attached through which air is extracted by a foot-operated vacuum pump. The instrument is placed on the descending head, creating a negative pressure on the skin of the scalp and enabling the operator to pull the head down. In mainland Europe, vacuum extraction is generally preferred to forceps for assisting natural deliveries, being used in around 5 per cent of all deliveries. Forceps have a greater risk of causing damage to the baby’s scalp and brain than vacuum extraction, although properly used, both types should not cause any serious damage to the baby.
Episiotomy Normal and assisted deliveries put the tissues of the genital tract under strain. The PERINEUM is less elastic than the vagina and, if it seems to be splitting as the baby’s head
moves down the birth canal, it may be necessary to cut the perineal tissue – a procedure called an episiotomy – to limit damage. This is a simple operation done under local anaesthetic. It should be done only if there is a speci?c indication; these include:
to hasten the second stage of labour if the fetus is distressed.
to facilitate the use of forceps or vacuum extractor.
to enlarge a perineum that is restricted because of unyielding tissue, perhaps because of a scar from a previous labour. Midwives as well as obstetricians are trained
to undertake and repair (with sutures) episiotomies.
(For organisations which o?er advice and information on various aspects of childbirth, including eclampsia, breast feeding and multiple births, see APPENDIX 2: ADDRESSES: SOURCES OF INFORMATION, ADVICE, SUPPORT AND SELF-HELP.)... pregnancy and labour
4 weeks pregnancy
"Pregnancy calendar" at 4th week: A miracle begins! Your baby, now consisting of a cell stack, is clinging to the walls of your uterus and starting to grow rapidly. Early pregnancy in this period, for example, nausea in pregnancy is extremely normal. Birth is a beautiful yet remote dream.
Your baby in 4 weeks pregnancy
Your baby is a seed of poppy seeds. By the end of the week your baby will be about 1 mm long.
Once the fertilized egg is placed on the side of your uterus, it divides into cell layers and becomes an embryo from official care. These cells turn into the body of your baby during pregnancy, forming the nervous system, skeleton, muscles and organs.
Support system in formation
The disc-like organ, which connects your body systems to the baby's systems, begins to form and attaches to the uterine wall where the egg is placed. The umbilical cord comes out of one of the placenta. Amniotic fluid, which will stretch your baby during pregnancy, has begun to form in a circumscribing membrane sac.
Your 4th week pregnancy
As the fertilized egg gets into your uterus, you may experience some bleeding. This is known as implantation hemorrhage and is completely normal.
The results came
Thanks to the brand-new placenta-attacked hCG hormone and a pregnancy test at home after the first period you missed, you will get a positive result, but false negative results can also be seen. This hormone is the greatest cause of nausea or morning sickness that many pregnant women experience in the first three months. If you are not pregnant, but your pregnancy test at home is negative, you may need a doctor.... pregnancy calendar - week 4 of your pregnancy
5-week pregnancy
"Pregnancy calendar" at week 5: Your baby's brain is developing. You may feel fears about pregnancy and birth during this period. These emotional fluctuations are normal, do not worry at all!
Baby for 5 weeks gestation
Your baby, between 1 and 2.5 mm, is a small orange seed.
Installation ready
The placenta and the umbilical cord that begins to form have begun to work to transfer the necessary nutrients from your body to the body of the baby. Oxygen, amino acids, fats and sugars all play a critical role in a healthy development.
Some basics
Some of Baby's cells turn into a nerve pathway that will form the backbone and brain. An incorrectly formed nerve pathway can lead to a complication called "discrete spine", a condition in which the spinal cord is not completely closed. Your best weapon against spinal cord birth defects is to take at least 400 micrograms of folic acid every day.
Heart start
The heart is now a single tube with a few irregular shots. With each passing week these shots will become more regular.
Your 5th week pregnancy
Emotional ocean
You may be very happy because you are pregnant, worried about everything being normal, fearful about birth, or not being sure of yourself as a mothers of mothers. Do not worry about it! All of these feelings are completely normal. By weekly calculation of pregnancy and birth calculation, keep your head busy dreaming about the birth of your baby.
Careful maintenance
At this stage of the pregnancy period, menstrual cramps and back pain are common. Take a break by taking a warm bath, listening to soothing music or taking a nap. Watch your food and if you have not done so, stop smoking, drinking alcohol or taking medication. All of this is harmful to your baby.... pregnancy calendar - week 5 of your pregnancy
A hearing test in which a vibrating tuning fork is placed on the mastoid process (see EAR). When the subject can no longer hear the ringing, it is placed beside the ear. Normal subjects can then hear the noise once more, but in people with conductive DEAFNESS, air conduction does not persist after bone conduction has ceased. It can help to distinguish between nerve (sensorineural) and conduction deafness.... rinnes test
A tube of thin glass closed at one end, which is used for observing chemical reactions or for bacterial culture.... test-tube
A mathematical formula (or function) that is used to determine if the difference between outcomes of a treatment or intervention and a control group is great enough to conclude that the difference is statistically significant. Statistical tests generate a value that is associated with a particular P value. Among the variety of common statistical tests are: F, t, Z, and chi-square. The choice of a test depends upon the conditions of the study, e.g. what type of outcome variable is used, whether or not the subjects are randomly selected from a larger population, and whether it can be assumed that the outcome values of the population have a normal distribution or other type of distribution.... statistical test
A positive tourniquet test with scattered fine petechiae is one of the earliest clinical signs in dengue haemorrhagic fever.... tourniquet test
The SCROTUM may be affected by various skin diseases, particularly eczema (see DERMATITIS) or fungal infection. A HERNIA may pass into the scrotum. Defective development of the testicles may lead to their retention within the abdomen, a condition called undescended testicle.
Hydrocoele is a collection of ?uid distending one or both sides of the scrotum with ?uid. Treatment is by withdrawal of the ?uid using a sterile syringe and aspiration needle.
Hypogonadism Reduced activity of the testes or ovaries (male and female gonads). The result is impaired development of the secondary sexual characteristics (growth of the genitals, breast and adult hair distribution). The cause may be hereditary or the result of a disorder of the PITUITARY GLAND which produces GONADOTROPHINS that stimulate development of the testes and ovaries.
Varicocoele is distension of the veins of the spermatic cord, especially on the left side, the causes being similar to varicose veins elsewhere (see VEINS, DISEASES OF). The chief symptom is a painful dragging sensation in the testicle, especially after exertion. Wearing a support provides relief; rarely, an operation may be advisable. Low sperm-count may accompany a varicocele, in which case surgical removal may be advisable.
Orchitis or acute in?ammation may arise from CYSTITIS, stone in the bladder, and in?ammation in the urinary organs, especially GONORRHOEA. It may also follow MUMPS. Intense pain, swelling and redness occur; treatment consists of rest, support of the scrotum, analgesics as appropriate, and the administration of antibiotics if a de?nitive microorganism can be identi?ed. In some patients the condition may develop and form an ABSCESS.
Torsion or twisting of the spermatic cord is relatively common in adolescents. About half the cases occur in the early hours of the morning during sleep. Typically felt as pain of varying severity in the lower abdomen or scrotum, the testis becomes hard and swollen. Treatment consists of immediate undoing of the torsion by manipulation. If done within a few hours, no harm should ensue; however, this should be followed within six hours by surgical operation to ensure that the torsion has been relieved and to ?x the testes. Late surgical attention may result in ATROPHY of the testis.
Tuberculosis may occur in the testicle, especially when the bladder is already affected. Causing little pain, the infection is often far advanced before attracting attention. The condition generally responds well to treatment with a combination of antituberculous drugs (see also main entry for TUBERCULOSIS).
Tumours of the testes occur in around 600 males annually in the United Kingdom, and are the second most common form of malignant growth in young males. There are two types: SEMINOMA and TERATOMA. When adequately treated the survival rate for the former is 95 per cent, while that for the latter is 50 per cent.
Injuries A severe blow may lead to SHOCK and symptoms of collapse, usually relieved by rest in bed; however, a HAEMATOMA may develop.... testicle, diseases of
See under TESTICLE, DISEASES OF.... undescended testis
Venereal Diseases Research Laboratory Test. One of the non-treponemal reaginic tests for syphilis.... vdrl test
A test with a tuning fork that is used to assess a person’s DEAFNESS.... weber’s test
An agglutination test used in the laboratory to diagnose rickettsial diseases. It depends on a nonspecific cross reaction between antibodies produced by the rickettsial infection with the OX-2, OX-19 and OXK antigens of the Gram negative rod, Proteus.... weil-felix test
A serological test used to detect antibodies in the diagnosis of typhoid. Antigens detected are the O (somatic), H (flagellar) and Vi (virulence) antigens.... widal test
The first intelligence test that attempted to measure higher mental functions, devised in 1905.... binet test
Tests to screen for and diagnose bleeding disorders, usually resulting from deficiencies or abnormalities of blood coagulation factors or of platelets (see blood clotting). Tests are also used to monitor treatment with anticoagulant drugs.... blood-clotting tests
One of a group of tests used to assess the function of the heart in people who experience chest pain, breathlessness, or palpitations during exercise. The test establishes whether the patient has coronary artery disease. An ECG machine records the patterns of the heart’s electrical activity while the heart is stressed. This is usually achieved by the patient exercising on a treadmill or cycling. Specific changes in the electrical pattern as exercise levels increase indicate angina. Cardiac stress testing may be used in conjunction with radionuclide scanning to identify damaged areas of heart muscle.... cardiac stress test
Analysis of a sample of blood to give information on its cells and proteins and any of the chemicals, antigens, antibodies, and gases that it carries. Such tests can be used to check on the health of major organs, as well as on respiratory function, hormonal balance, the immune system, and metabolism. Blood tests may look at numbers, shape, size, and appearance of blood cells and assess the function of clotting factors. The most important tests are blood count and blood group tests if transfusion is needed. Biochemical tests measure chemicals in the blood (see acid–base balance; kidney function tests; liver function tests). Microbiological tests (see immunoassay) look for microorganisms that are in the blood, as
in septicaemia. Microbiology also looks for antibodies in the blood, which may confirm immunity to an infection. blood transfusion The infusion of large volumes of blood or blood products directly into the bloodstream to remedy severe blood loss or to correct chronic anaemia. In an exchange transfusion, nearly all of the recipient’s blood is replaced by donor blood. Before a transfusion, a sample of the recipient’s blood is taken to identify the blood groups, and it is matched with suitable donor blood. The donor blood is transfused into an arm vein through a plastic cannula. Usually, each unit (about 500 ml) of blood is given over 1–4 hours; in an emergency, 500 ml may be given in a couple of minutes. The blood pressure, temperature, and pulse are monitored during the procedure.
If mismatched blood is accidentally introduced into the circulation, antibodies in the recipient’s blood may cause donor cells to burst, leading to shock or kidney failure. Less severe reactions can produce fever, chills, or a rash. Reactions can also occur as a result of an allergy to transfused blood components. All
blood used for transfusion is carefully screened for a number of infectious agents, including HIV (the AIDS virus) and hepatitis B and hepatitis C.
In elderly or severely anaemic patients, transfusion can overload the circulation, leading to heart failure.
In patients with chronic anaemia who need regular transfusion over many years, excess iron may accumulate (haemosiderosis) and damage organs such as the heart, liver, and pancreas.
Treatment with desferrioxamine to remove excess iron may be needed.... blood tests
A test for meningitis that involves pressing a clear glass against a rash. If the rash remains visible, it may be a form of purpura, which sometimes occurs in meningitis.... glass test
An outdated psychological test in which the subject was asked to interpret the appearance of a number of ink blots. The most widely used example was the Rorschach test.... ink-blot test
See pulmonary function tests.... lung function tests
See pregnancy, multiple.... multiple pregnancy
Questionnaires designed to define various personality traits or types. Tests may be designed to detect psychiatric symptoms, underlying personality traits, how outgoing or reserved a person is, and predisposition to developing neurotic illness.... personality tests
See Guthrie test.... pku test
See pulmonary function tests.... respiratory function tests
A type of intelligence test.... stanford–binet test
See abortion, induced.... termination of pregnancy
A rare, cancerous tumour of the testis. Testicular cancer is most common in young to middle-aged men, and the risk increases in individuals with a history of undescended testis (see testis, undescended). The most common types of testicular cancer are seminomas, which are made up of only 1 type of cell, and teratomas. The cancer usually appears as a firm, painless swelling of 1 testis. There may also be pain and inflammation. Biopsy, followed by orchidectomy, is the usual treatment, and may be combined with chemotherapy. The tumours usually respond well to treatment.... testis, cancer of
A testis that is absent from the scrotum because it has descended into an abnormal position, usually in the groin or at the base of the penis. The condition is most often discovered soon after birth during a routine physical examination. It is treated by orchidopexy. (See also testis, undescended.) ... testis, ectopic
Pain in a testis may be caused by mild injury, a tear in the wall of the testis due to a direct blow, orchitis, epididymo-orchitis, and torsion of the testis (see testis, torsion of). Sometimes, no cause is found and the pain disappears without treatment. If the wall of the testis is torn, an operation to repair it may be needed. ... testis, pain in the
Swelling of the testis or the surrounding tissues in the scrotum. Harmless and painless swellings include epididymal cysts, hydroceles, varicoceles, and spermatoceles. Cancer of the testis (see testis, cancer of) is rare but may be a cause of painless swelling. Swelling that is painful may be caused by a direct blow, torsion of the testis (see testis, torsion of), orchitis, epididymoorchitis, or, in very rare cases, cancer of the testis. Any swelling of the testes should be assessed promptly by a doctor.... testis, swollen
A group of blood tests used to evaluate the function of the thyroid gland and to detect or confirm any thyroid disorder. The thyroid hormones T3 and T4 are measured, as well as thyroid-stimulating hormone (TSH), the pituitary gland hormone that stimulates the thyroid gland.... thyroid-function tests
See preeclampsia.... toxaemia of pregnancy
Skin tests used to determine whether or not a person has been exposed to the bacterium that causes tuberculosis. Tuberculin tests are carried out for diagnosis of tuberculosis, and before BCG vaccination. A small amount of tuberculin (purified protein from the bacteria) is injected into the skin. A few days later, the skin reaction, if any, is noted. A reaction indicates previous exposure.... tuberculin tests
Hearing tests carried out to diagnose conductive deafness. In the Weber test, a vibrating tuning fork is held against the forehead. If there is conductive hearing loss, the sound seems louder in the affected ear. In the Rinne test, a vibrating tuning fork is held first near the ear, and then against the bone behind it. If it sounds louder when held against the bone, there is conductive hearing loss.... tuning fork tests
See urinalysis.... urine tests
a rare and life-threatening complication of pregnancy that usually presents in the third trimester with symptoms of nausea, vomiting, malaise, and abdominal pain. Liver function tests are abnormal and the features of *pre-eclampsia and often *HELLP syndrome are present. *Hepatic encephalopathy, *disseminated intravascular coagulation, and renal failure may develop, and the condition is associated with a high maternal and fetal mortality. Treatment involves a multidisciplinary approach, usually in an intensive care unit.... acute fatty liver of pregnancy
a test for the presence of sugar in urine or other liquids. A few drops of the test solution are added to Benedict’s solution, prepared from sodium or potassium citrate, sodium carbonate, and copper sulphate. The mixture is boiled and shaken for about two minutes, then left to cool. The presence of up to 2% glucose is indicated by the formation of a reddish, yellowish, or greenish precipitate, the highest levels corresponding to the red coloration, the lowest (about 0.05%) to the green. [S. R. Benedict (1884–1936), US surgeon]... benedict’s test
where clinical *negligence is claimed, tests used to determine the standard of care owed by professionals to those whom they serve, e.g. the standards of care provided to patients by doctors. The 1957 case of Bolam v Friern Hospital Management Committee established that if a doctor acts in accordance with a responsible body of medical opinion, he or she will not be negligent. In 1997 this standard of care test was amended by the case of Bolitho v City and Hackney Health Authority, which requires the doctor’s behaviour to satisfy the judgment not only of responsible medical opinion but also of a court’s own independent logical analysis.... bolam and bolitho tests
(in statistics) a test to determine if the difference between two groups of observations is statistically significant (see significance), used in controlled trials and other studies. It measures the differences between theoretical and observed values and identifies whether or not *variables are related.... chi-square test
a test used to detect a squint. The observer looks at a target object, one eye at a time being covered. If the uncovered eye deviates to focus on the target, then a squint is confirmed. The movement can be up, down, sideways, or a combination, depending on the type of squint (see strabismus).... cover test
a screening tool for young people under the age of 21 to identify alcohol and drug use. The first part consists of three questions about drug or alcohol use over the past year. Participants giving positive answers to two or more questions proceed to the second part (from which the name derives), which contains six questions with the key words car, relax, alone, family/friends, forget, trouble, used to assess the need for further input.... crafft screening test
a hearing test used for screening infants between the ages of six and ten months. The infant is placed on its carer’s knee, one examiner sits in front of the infant and gains its attention, and a second examiner is situated just behind the infant. At a given moment the first examiner becomes very still and the second examiner makes a sound at the level of the infant’s ear to one side or the other. If the infant can hear it turns in the direction of the sound. The sounds made should be of different pitches and a given loudness.... distraction test
(DSTs) tests based on the principle that appropriate doses of *dexamethasone can suppress the output of cortisol from the adrenal glands in the normal state and that this ability is reduced or lost in *Cushing’s syndrome. In the overnight DST 1 mg of dexamethasone is administered at midnight and the serum cortisol level is measured at 9.00 am the next morning. Failure to suppress cortisol output may indicate Cushing’s syndrome but also occurs in patients with obesity and depressive illness. In the low-dose DST (0.5 mg dexamethasone every 6 hours for 48 hours), cortisol suppression occurs in patients with obesity and depression but not in those with Cushing’s syndrome. In the high-dose DST (2 mg dexamethasone every 6 hours for 48 hours), cortisol is suppressed in patients with Cushing’s disease (in which excess amounts of ACTH are secreted by the pituitary gland) but not in those with Cushing’s syndrome due to other causes. Although the low- and high-dose tests are unreliable, all three tests should be performed to aid the diagnosis of Cushing’s syndrome.... dexamethasone suppression tests
(Hallpike test) a test for *benign paroxysmal positional vertigo (BPPV), performed with the patient first sitting upright on an examination couch and then lying supine with the head and neck extended beyond the edge of the couch. The patient’s head is rotated to the left (or right) and supported by the examiner while the patient assumes the supine position and keeps his or her eyes focused on the examiner’s eyes. The test is then repeated with the other ear facing down. In patients with BPPV, after a short delay rotatory *nystagmus is seen, in association with severe vertigo and nausea, which gradually abates. The effect diminishes with repeated manoeuvres. In conditions affecting the cerebellum or brainstem, the nystagmus occurs immediately, in any direction, and does not diminish, and patients do not feel especially nauseated. [M. R. Dix and C. S. Hallpike (20th century), British otologists]... dix–hallpike test
(FOBT) a noninvasive test used to identify microscopic blood (see occult) in faeces. It is widely used as a screening test for colorectal cancer.... faecal occult blood test
see pseudocyesis.... false pregnancy
a test for detecting the presence of sugar in urine, which has now been replaced by better and easier methods. [H. von Fehling (1812–85), German chemist]... fehling’s test
a test for folate or vitamin B12 deficiency. A dose of the amino acid histidine, which requires the presence of folate or vitamin B12 for its complete breakdown, is given by mouth. In the absence of these vitamins, formiminoglutamic acid (figlu) – an intermediate product in histidine metabolism – accumulates and can be detected in the urine.... figlu test
a test for *ataxia or cerebral lesions. Using the index finger, the patient alternately touches his or her nose and then the examiner’s finger, which is shifted to a new position for each of the patient’s movements. The test is positive if the patient misses a target or develops a tremor as the target is approached (intention tremor).... finger–nose test
(FPL test) a test used to evaluate the *visual acuity of infants and young children by observing whether the child looks at a blank screen or one with stripes, the spatial frequency of which can be changed.... forced preferential looking test
see forced preferential looking test.... fpl test
a rarely used diagnostic test for the sexually transmitted disease *lymphogranuloma venereum. A small quantity of the virus, inactivated by heat, is injected into the patient’s skin. If the disease is present a small red swelling appears at the site of injection within 48 hours. [W. S. Frei (1885–1943), German dermatologist]... frei test
a test for *phaeochromocytomas not displaying typically high levels of plasma *catecholamines. An intravenous bolus of *glucagon is administered and the test is positive when there is a threefold increase in plasma catecholamine levels with a consequent rise in blood pressure. The test is now very rarely used due to safer and more sensitive screening tests, combined with modern tumour imaging techniques.... glucagon stimulation test
(heel-prick blood test) a blood test performed on all newborn babies at the end of the first week of life. The blood is obtained by pricking the heel of the baby. The test can detect several *inborn errors of metabolism (including *phenylketonuria) and *hypothyroidism; it can also be used for detecting *cystic fibrosis, although this is not routinely offered. [R. Guthrie (1916–95), US paediatrician]... guthrie test
see Dix–Hallpike test.... hallpike test
see Guthrie test.... heel-prick blood test
a test for the presence of protein (albumin) in the urine. A quantity of urine is carefully poured onto the same quantity of pure nitric acid in a test tube. A white ring forms at the junction of the liquids if albumin is present. However, a similar result may be obtained if the urine contains certain drugs or is very concentrated. A dark brown ring indicates the presence of an abnormally high level of potassium indoxyl sulphate in the urine (see indicanuria). [J. F. Heller (1813–71), Austrian pathologist]... heller’s test
an important but potentially dangerous test of anterior pituitary function involving the deliberate induction of a hypoglycaemic episode with injected insulin and the subsequent measurement of plasma cortisol and growth hormone at regular intervals over the next three hours. The stress of the hypoglycaemia should induce a rise in the levels of these hormones unless the anterior pituitary or the adrenal glands are diseased. The test can induce epileptic seizures or angina in those with a predisposition and should not be performed in susceptible individuals. It is often combined with the thyrotrophin-releasing hormone (TRH) test and the gonadotrophin-releasing hormone (GnRH) test in what is known as the triple test (or dynamic pituitary function test).... insulin stress test
a card with text printed in type of different sizes, used for testing acuity of near vision. [E. R. Jaeger von Jastthal (1818–84), Austrian ophthalmologist]... jaeger test types
a test to detect and measure fetal red blood cells in the maternal circulation of Rh-negative women who have *antepartum haemorrhage or have previously had a Rh-positive baby. It is used to calculate the correct dose of *anti-D immunoglobulin that will prevent *haemolytic disease of the newborn.... kleihauer–betke test
a test of the ability of the pituitary to secrete growth hormone, in which levodopa is administered by mouth and plasma levels of growth hormone are subsequently measured (they should peak within the following hour). It is a safer alternative to the *insulin stress test but does not give information on cortisol production, which is usually more clinically important to know.... levodopa test
see significance.... mann–whitney u test
a hearing test used in preschool children in which the child must discriminate between similar speech sounds. The test consists of 14 toys that are paired because their names sound similar; for example, tree and key, plane and plate. Having first identified all the objects, the child is then asked in a quiet voice to indicate a particular toy (e.g. Can you find the key?).... mccormick toy test
a simple noninvasive procedure that enables the detection of *carriers for single gene defects, e.g. *cystic fibrosis. Epithelial cells from the buccal cavity are obtained from a saline mouthwash: from these it is possible to isolate DNA, which is amplified by the *polymerase chain reaction to enable gene analysis.... mouthwash test
a three-question tool designed to uncover any connection between an individual’s attendance at an A & E department and alcohol-related problems, thereby creating the potential for intervention and referral.... paddington alcohol test
see significance.... parametric test
see pseudocyesis.... phantom pregnancy
(PEP) intensely itchy papules and weals on the abdomen (except the umbilicus), upper limbs, and buttocks, usually within the *striae gravidarum; it is also known as PUPPP (pruritic urticarial papules and plaques of pregnancy). It occurs in 1 in 250 first pregnancies late in the third trimester. This condition is harmless to mother and baby, but can be very annoying. It lasts an average of 6 weeks and resolves spontaneously 1–2 weeks after delivery. The most severe itching normally lasts for no more than a week.... polymorphic eruption of pregnancy
a test used in the investigation of infertility. A specimen of cervical mucus, taken 6–24 hours after coitus, is examined under a microscope. The appearance of 10 or more progressively motile spermatozoa per high-power field in the specimen indicates that there is no abnormal reaction between spermatozoa and mucus. The test should be undertaken in the postovulatory phase of the menstrual cycle.... postcoital test
a pregnancy that has gone beyond 42 weeks gestation or 294 days from the first date of the last menstrual period.... post-term pregnancy
(pregnancy tumour, granuloma gravidarum) a benign growth on the gums caused by inflammation of the gingivae during pregnancy. This type of *epulis may not need any specific treatment as it often shrinks post-partum.... pregnancy epulis
(PIH) raised blood pressure (>140/90 mmHg) developing in a woman during the second half of pregnancy. It usually resolves within six weeks of delivery and is associated with a better prognosis than *pre-eclampsia.... pregnancy-induced hypertension
(PUL) a positive pregnancy test when no fetus can be seen on an ultrasound scan, which is due to a very early ongoing pregnancy, an early failing pregnancy, or an ectopic pregnancy not located on scan.... pregnancy of unknown location
(in psychology) a way of measuring aspects of personality, in which the subject is asked to talk freely about ambiguous objects. His responses are then analysed. Examples are the *Rorschach test and the Thematic Apperception Test (in which the subject invents stories about a set of pictures).... projective test
a part of the routine *lumbar puncture procedure. It is used to determine whether or not the flow of cerebrospinal fluid is blocked in the spinal canal. [H. H. G. Queckenstedt (1876–1918), German physician]... queckenstedt test
tests for assessing the function of the kidneys. These include measurements of the specific gravity of urine, creatinine *clearance time, and blood urea levels; intravenous urography; and renal angiography.... renal function tests
a test to determine whether *deafness is conductive or sensorineural. A vibrating tuning fork is held first in the air, close to the ear, and then with its base placed on the bone (mastoid process) behind the ear. If the sound conducted by air is heard louder than the sound conducted by bone the test is positive and the deafness sensorineural; a negative result, when the sound conducted by bone is heard louder, indicates conductive deafness. [H. A. Rinne (1819–68), German otologist]... rinne’s test
a method of testing urine for the presence of acetone or acetoacetic acid: a sign of *diabetes mellitus. Strong ammonia is added to a sample of urine saturated with ammonium sulphate crystals and containing a small quantity of sodium nitroprusside. A purple colour confirms the presence of acetone or acetoacetic acid. [A. C. H. Rothera (1880–1915), Australian biochemist]... rothera’s test
a test to determine whether a person is susceptible to diphtheria. A small quantity of diphtheria toxin is injected under the skin; a patch of reddening and swelling shows that the person has no immunity and – if at particular risk – should be immunized. With safer *toxoids, this test is no longer necessary. [B. Schick (1877–1967), US paediatrician]... schick test
a test used to assess a patient’s capacity to absorb vitamin B12 from the bowel. Radioactive vitamin B12 is given by mouth and urine collected for 24 hours. A normal individual will excrete at least 10% of the original dose over this period; a patient with *pernicious anaemia will excrete less than 5%. [R. F. Schilling (1919), US physician]... schilling test
a test for detecting visual impairment in children who are too young to be able to read the *Snellen chart. A series of cards, each marked with a single letter of a specific size, are held up at a distance of 6 metres from the child being tested. The child is provided with an identification card containing a selection of letters and is asked to point to the letter that is the same as the one on the card in the distance. The test is suitable for children between the ages of two and seven.... sheridan–gardiner test
an investigation to seek evidence of cardiac *ischaemia. The heart is stressed by exercise or by the administration of an intravenous drug that increases heart rate (i.e. mimicked exercise). Ischaemia may then be detected by electrocardiography (stress ECG or exercise ECG), *echocardiography (showing the development of impaired function in areas of heart muscle that are ischaemic), *myocardial perfusion scan, or cardiac MRI.... stress test
see significance. [Pseudonym of W. S. Gosset (1876–1937), British statistician]... student’s t test
Standard Tests for Young Children and Retardates: tests to detect visual problems in children between the ages of six months and five years. They consist of a series of standardized balls, toys, or letters. The tests were developed by the paediatrician Mary Sheridan.... stycar tests
tests used to assess the ability of the adrenal cortex to produce cortisol. Serum cortisol is measured before and then 30 minutes (or 5 hours) after an intramuscular injection of 250 ?g (or 1 mg) tetracosactide (Synacthen), an analogue of *ACTH. The adrenal glands are considered to be inadequate if there is a low baseline concentration of cortisol or the rise is less than a certain predefined amount.... synacthen tests
(Trendelenburg’s sign) a test for detecting dysfunction of the hip joint. Normally when a leg is lifted off the ground, the pelvis on the same side is raised by the hip abductor muscles on the other side. If these muscles cannot raise the pelvis against body weight, the pelvis will tilt downwards and the test is positive, indicating arthritis, paralysis of the muscles due to superior gluteal nerve injury, or other hip pathology (e.g. congenital hip dislocation). [F. Trendelenburg]... trendelenburg’s test
1. (in *prenatal screening) a blood test that can be performed between the 15th and 20th weeks of pregnancy but has largely been replaced by combined first-trimester *PAPP-A screening and *nuchal translucency scanning. Levels of *alpha-fetoprotein (AFP), *unconjugated oestriol (uE3), and *human chorionic gonadotrophin (hCG) in the serum are computed with maternal age to determine the statistical likelihood of the fetus being affected by Down’s syndrome or spina bifida. The double test is similar but omits measurement of uE3. 2. see insulin stress test.... triple test
(VEMP) a test used to measure the response of the *saccule. It is used in the diagnosis of *superior canal dehiscence syndrome, *Ménière’s disease, and other disorders of the inner ear.... vestibular evoked myogenic potential test
a test for *diabetes insipidus in which fluid and food intake is withheld completely for up to 24 hours, with regular measurement of plasma and urinary *osmolality and body weight. Normally (and in a person with psychogenic *polydipsia) the output of *vasopressin will be increased in order to concentrate the urine as the plasma osmolality rises; correspondingly, the urine osmolality also rises and its volume diminishes. In a patient with diabetes insipidus, however, the urine osmolality will remain low and of high volume while the patient steadily dehydrates. The test must be abandoned if the patient loses 3% of body weight.... water-deprivation test
a hearing test in which a vibrating tuning fork is placed at the midpoint of the forehead. A normal individual hears it equally in both ears, but if one ear is affected by conductive *deafness the sound appears louder in the affected ear. If one ear has a sensorineural deafness the sound appears louder in the unaffected ear. [F. E. Weber (1832–91), German otologist]... weber’s test
a direct percutaneous renal infusion test to investigate possible obstruction of the ureter or kidney. It detects subtle obstructions that cannot be detected by imaging. [R. Whitaker (20th century), British urologist]... whitaker’s test
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