For woman about to have a baby , the process of labour is induced in as many as 1 in 5 births because of maternal and fetal reasons. These reasons can include high blood pressure, heart or kidney disease in the mom, premature rupture of membranes or a pregnancy that has gone to long. Other reasons include a baby that has stopped growing.

Induction artificially prepares the cervix to open and initiates labour. Popular belief is that induction increases risk of caesarean delivery but does it?

In this week's CMAJ the risk of a caesarean delivery was 12 per cent lower in women whose labour was induced compared with women who were managed with a "wait-and-see" approach - so called expectant management.

Induction is often thought to be associated with increased risk of caesarean deliveries despite evidence indicating a lower risk. However, much of this evidence is weak.

The study looks at  157 randomized controlled trials that included 31 085 deliveries to determine whether there is an increased risk of caesarean delivery associated with induction compared with expectant management.

The authors found that the risk of caesarean delivery following labour induction was significantly lower than the risk associated with expectant management.

The study found a 12 per cent lower risk of caesarean delivery in term or post-term pregnancies that were induced but not in preterm births. The risk was lower in both high-risk and low-risk pregnancies, and the risk of fetal death or complications was lower in women who were induced compared with those managed expectantly.

In fact, induction is a way to increase the likelihood of a vaginal birth.

The authors also found that what was used to induce labour also made a difference. Prostaglandin E2, which is commonly used in the U.K., Canada and the United States to induce labour, was associated with significant reductions in the risk of caesarean delivery. Other drugs such as oxytocin, and amniotomy which is artificial rupture of the membranes, also widely used, did not show a decreased risk of caesarean delivery.

The authors say that women whose labour was induced were less likely than those managed expectantly to have a caesarean delivery. In addition, the risk of fetal death and admission to neonatal intensive care unit were decreased in the induction group.