The appearance in labour of some particular part of the child’s body at the mouth of the uterus (see PREGNANCY AND LABOUR). This is a head presentation in 96 per cent of cases, but in a certain number the breech (or buttocks) may present, or the face, or foot, or even a part of the trunk in cases of cross-birth.
The term is also used for the symptoms or signs with which a patient ?rst brings to a doctor.
n. the part of the fetus that is closest to the birth canal and can be felt on inserting a finger into the vagina. Normally the back of the head (vertex) presents, the most favourable position for delivery being occipital anterior (see occiput). However, the buttocks may present (see breech presentation) or, if the fetus lies transversely across the uterus, the shoulder or arm may present (see malpresentation). These abnormal presentations may cause complications during childbirth, and attempts may be made to correct them. See also denominator.
By the 32nd week of pregnancy most babies are in a head-down position in the womb. Up to 4 per cent of them, however, have their buttocks (breech) presenting at the neck of the womb. If the baby is still a breech presentation at the 34th to 35th week the obstetrician may, by external manipulation, try to turn it to the head-down position. If this is not successful, the fetus is left in the breech position. Breech deliveries are more di?cult for mother and baby because the buttocks are less e?cient than the head at dilating the cervix and vagina. An EPISIOTOMY is usually necessary to assist delivery, and obstetric FORCEPS may also have to be applied to the baby’s head. If the infant and/or the mother become unduly distressed, the obstetrician may decide to deliver the baby by CAESAREAN SECTION; some obstetricians prefer to deliver most breech-presentation babies using this method. (See PREGNANCY AND LABOUR.)... breech presentation
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