Induction

There are few absolute indications for inducing labour, and priorities vary with the obstetrician. Postmaturity (when the pregnancy extends well beyond the expected delivery date) still heads the list, followed by suspected fetal growth retardation and maternal hypertension. Social factors—such as the woman’s own wishes—play a larger part these days. In a meta-analysis of 10 randomised controlled trials comparing induction at 41-42 weeks with conservative treatment, Crowley showed the increased risk of perinatal deaths associated with prolonged pregnancy. The risk is reduced by induction at 41 weeks (Cochrane Collaboration). A non-medical indication for induction is the woman’s own wishes. Many mothers exceeding their expected delivery date by a week consider that their pregnancy has gone far enough and ask for induction. Roberts and Young found that about 70% of women expressed the wish to be induced after 41 weeks. Provided that the cervix is ripe, many obstetricians would agree with this choice and use a non-invasive method—for example, prostaglandins. Maternal age and poor obstetric history are relative indications, but it should be remembered that induction is intended to result in a birth. Hence, if a vaginal delivery does not follow, a caesarean section may be required. If the grounds for induction are not strong, this could lead to a caesarean section for a poor indication. Rarely, a planned time of delivery may be needed to provide the best care for the fetus. Some cardiac abnormalities may require immediate surgery after birth. Labour should be induced at a tertiary referral centre, with the facilities for neonatal surgery ready.