Fetal distress Health Dictionary

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Fetal Distress: From 1 Different Sources

The physical stress experienced by a fetus during labour as a result of its not receiving enough oxygen. During a contraction, the uterus tightens and reduces the oxygen supply from the placenta to the fetus. If, in addition, there are problems, such as pressure on the umbilical cord or the mother’s losing blood, there may be an inadequate amount of oxygen reaching the fetus.

Fetal distress may cause the baby’s heart-rate to slow or to fail to show normal variability, which can be recorded on a cardiotocograph (see fetal heart monitoring). Acidosis (high acidity in the body), which can be detected in a sample of blood taken from the scalp, indicates that the oxygen supply to the fetus is inadequate. Signs of meconium in the amniotic fluid can also be an indication of fetal distress.

Fetal distress sometimes occurs as a temporary episode, but, if acidosis is severe, the distressed fetus may need to be delivered promptly by caesarean section, forceps delivery, or vacuum extraction. (See also childbirth.)

Health Source: BMA Medical Dictionary
Author: The British Medical Association

Fetal Blood Sampling

A procedure performed during a mother’s labour in which a blood sample is taken from a vein in the scalp of the FETUS. This enables tests to be performed that indicate whether the fetus is, for example, suffering from a shortage of oxygen (HYPOXIA). If so, the obstetrician will usually accelerate the baby’s birth.... fetal blood sampling

Fetal Transplant

A procedure in which cells – for example, from the pancreas – are taken from an aborted FETUS and then transplanted into the malfunctioning organ (pancreas) of an individual with a disorder of that organ (in this case, diabetes). The cells from the fetus are intended to take over the function of the host’s diseased or damaged cells. Fetal brain cells have also been transplanted into brains of people suffering from PARKINSONISM. These treatments are at an experimental stage.... fetal transplant

Respiratory Distress Syndrome

This may occur in adults as ACUTE RESPIRATORY DISTRESS SYNDROME (ARDS), or in newborn children, when it is also known as HYALINE MEMBRANE DISEASE. The adult syndrome consists of PULMONARY OEDEMA of non-cardiac origin. The process begins when tissue damage stimulates the autonomic nervous system, releases vasoactive substances, precipitates complement activation, and produces abnormalities of the clotting cascade – the serial process that leads to clotting of the blood (see COAGULATION). The activation of complement causes white cells to lodge in the pulmonary capillaries where they release substances which damage the pulmonary endothelium.

Respiratory distress syndrome is a complication of SHOCK, systemic SEPSIS and viral respiratory infections. It was ?rst described in 1967, and – despite advances with assisted ventilation

– remains a serious disease with a mortality of more than 50 per cent. The maintenance of adequate circulating blood volume, peripheral PERFUSION, acid-base balance and arterial oxygenation is important, and assisted ventilation should be instituted early.

In newborns the mechanism is diferent, being provoked by an inability of the lungs to manufacture SURFACTANT.... respiratory distress syndrome

Acute Respiratory Distress Syndrome (ards)

Formerly known as adult respiratory distress syndrome. A form of acute respiratory failure in which a variety of di?erent disorders give rise to lung injury by what is thought to be a common pathway. The condition has a high mortality rate (about 70 per cent); it is a complex clinical problem in which a disproportionate immunological response plays a major role. (See IMMUNITY.)

The exact trigger is unknown, but it is thought that, whatever the stimulus, chemical mediators produced by cells of the immune system or elsewhere in the body spread and sustain an in?ammatory reaction. Cascade mechanisms with multiple interactions are provoked. CYTOTOXIC substances (which damage or kill cells) such as oxygen-free radicals and PROTEASE damage the alveolar capillary membranes (see ALVEOLUS). Once this happens, protein-rich ?uid leaks into the alveoli and interstitial spaces. SURFACTANT is also lost. This impairs the exchange of oxygen and carbon dioxide in the lungs and gives rise to the clinical and pathological picture of acute respiratory failure.

The typical patient with ARDS has rapidly worsening hypoxaemia (lack of oxygen in the blood), often requiring mechanical ventilation. There are all the signs of respiratory failure (see TACHYPNOEA; TACHYCARDIA; CYANOSIS), although the chest may be clear apart from a few crackles. Radiographs show bilateral, patchy, peripheral shadowing. Blood gases will show a low PaO2 (concentration of oxygen in arterial blood) and usually a high PaCO2 (concentration of carbon dioxide in arterial blood). The lungs are ‘sti?’ – they are less e?ective because of the loss of surfactant and the PULMONARY OEDEMA.

Causes The causes of ARDS may be broadly divided into the following:... acute respiratory distress syndrome (ards)

Fetal Alcohol Syndrome

A disorder of newborn infants that is caused by the toxic effects on the growing FETUS of excessive amounts of alcohol taken by the mother. Low birth-weight and retarded growth are the main consequences, but affected babies may have hand and facial deformities and are sometimes mentally retarded.... fetal alcohol syndrome

Fetal Circulation

Blood circulation in the fetus is different from the normal circulation after birth (see circulatory system). The fetus neither breathes nor eats. Therefore, oxygen and nutrients are obtained and waste products such as carbon dioxide are removed via the placenta. Fetal blood reaches the placenta through blood vessels in the umbilical cord. The maternal and fetal circulations are separated by a thin membrane in the placenta, which allows the exchange of nutrients and waste products.

The other fundamental difference in circulation is that most blood bypasses the lungs in the fetus through 2 special channels in the fetal heart.

Blood passes from the right atrium of the heart to the left atrium through the foramen ovale.

Another channel, known as the ductus arteriosus, allows blood to pass from the pulmonary artery to the aorta.

Both channels normally close after birth.

In rare cases, they fail to close, causing a congenital heart disorder (see heart disease, congenital).... fetal circulation

Acute Respiratory Distress Syndrome

see adult respiratory distress syndrome.... acute respiratory distress syndrome

Adult Respiratory Distress Syndrome

(acute respiratory distress syndrome, ARDS) a form of *acute respiratory failure that occurs after a precipitating event, such as trauma, aspiration, or inhalation of a toxic substance; it is particularly associated with septic shock. Lung injury is characterized by reduced oxygen in the arteries, reduced lung volume, and decreased lung compliance, and diffuse infiltrates are seen on a chest X-ray. Treatment is correction of the original cause, volume replacement, diuretics, oxygen, and mechanical ventilation.... adult respiratory distress syndrome

Fetal Alcohol Spectrum Disorder

(FASD, fetal alcohol syndrome, FAS) a condition of newborn babies that results from the toxic effects on the fetus of maternal alcohol abuse. Babies have a low birth weight and growth is retarded. They have a small head (*microcephaly), low-set ears, eye, nose, lip, and nail abnormalities, and disturbances of behaviour and intellect. The greater the alcohol abuse, the more severe the fetal manifestations.... fetal alcohol spectrum disorder

Fetal Heart Monitoring

The use of an instrument to record and/or listen to an unborn baby’s heartbeat during pregnancy and labour. Monitoring is carried out at intervals throughout pregnancy if tests indicate that the placenta is not functioning normally or if the baby’s growth is slow. During labour, monitoring can detect fetal distress, in which oxygen deprivation causes abnormality in the fetal heart-rate.

The simplest form of fetal heart monitoring involves the use of a special fetal stethoscope. Cardiotocography, a more sophisticated electronic version, makes a continuous paper recording of the heartbeat together with a recording of the uterine contractions. The heartbeat is picked up either externally by an ultrasound transducer strapped to the mother’s abdomen or, as an alternative during labour, internally by an electrode attached to the baby’s scalp that passes through the vagina and cervix.... fetal heart monitoring

Fetal Growth Chart

a graph, customized to a pregnant woman’s height, weight, and other factors, that plots *fundal height and estimated fetal weight on ultrasound against weeks of gestation. The graph, which shows centile lines (see centile chart), improves prediction of a baby who is *small for gestational age.... fetal growth chart

Fetal Growth Restriction

see intrauterine growth restriction.... fetal growth restriction

Fetal Implant

(fetal graft) the introduction of an ovum, fertilized in vitro and developed to the *blastocyst stage, into the uterus of a postmenopausal woman in order that she may become pregnant. Before this procedure, the woman’s uterus must be prepared, by hormone therapy, to receive and nurture the blastocyst. Hormone treatment is continued throughout the pregnancy.... fetal implant

Fetal Scalp Electrode

an electrical wire set into a sharp spiral metal tip and encased in a plastic sheath. It is attached to the fetal scalp for direct measurement of fetal heart rate by electrical activity.... fetal scalp electrode

Intrauterine Fetal Death

death of a fetus in the uterus after 24 weeks of gestation. See stillbirth.... intrauterine fetal death

Respiratory Distress

severe difficulty in achieving adequate oxygenation in spite of significant efforts to breathe: it is usually associated with increased *respiratory rate and the use of *accessory muscles in the chest wall. It can occur in both obstructive and nonobstructive lung conditions. See adult respiratory distress syndrome; airway obstruction; dyspnoea; respiratory distress syndrome; stridor.

respiratory distress syndrome (RDS; hyaline membrane disease) the condition of a newborn infant in which the lungs are imperfectly expanded. Initial inflation and normal expansion of the lungs requires the presence of a substance (*surfactant) that reduces the surface tension of the air sacs (alveoli) and prevents collapse of the small airways. Without surfactant the airways collapse, leading to inefficient and ‘stiff’ lungs. The condition is most common and serious among preterm infants, in whom surfactant may be deficient. It lasts 5–10 days, with worsening on days 2–3. Breathing is rapid, laboured, and shallow, and microscopic examinations of lung tissue in fatal cases has revealed the presence of *hyalin material in the collapsed air sacs. The condition is treated by careful nursing, intravenous fluids, and oxygen, with or without positive-pressure ventilation (see noninvasive ventilation). Early surfactant replacement therapy has been shown to reduce the severity of RDS and when given prophylactically it has been demonstrated to improve clinical outcome. See also adult respiratory distress syndrome.... respiratory distress


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