Childbirth

Childbirth (also called labour, birth, or parturition) is the process at the end of pregnancy by which a fetus leaves the mother's womb.

A typical human childbirth will begin the onset of the first stage of labour: contractions of the uterus, at first every 10-30 minutes and lasting about 40 seconds each, and the rupture of the amniotic sac ("breaking of the water"). The contractions will accelerate until they happen every two minutes. Each contraction dilates the cervix until it reaches ten centimetres (4") in width.

In the second stage of labour, the baby is expelled from the womb through the birth canal by both the uterine contractions and by powerful abdominal contractions ("bearing down"). The baby is most commonly born head-first.

The last stage of labour occurs about a quarter to a half-hour after the baby is born; in this stage, the placenta or afterbirth is expelled.

The duration of labour varies wildly, but averages some 13 hours for women giving birth to their first child ("primiparae") and 8 hours for women who have already given birth.

Due to the shape of the human pelvis forced by the erect posture, human childbirth is more painful than that of other mammals. A variety of anaesthetics have come into use to alleviate labour pains.

Complications occasionally obtain during childbirth; this can require interventions such as Caesarian section. In the past, a great many women died during childbirth (see puerperal fever) but modern medical techniques available in industrialized countries have greatly reduced this total.

The medical science of childbirth is obstetrics; a doctor who specializes in attending births is an obstetrician. A person who is not a doctor but who is specially trained to assist at births is a midwife.