Does routine induction of labour at 41 weeks really reduce the rate of caesarean section compared with expectant...

It is contended that routine induction of labour at 41 completed weeks of gestation reduces, or at least does not increase, a woman's chance of Caesarean section (CS), compared with expectant management. We wanted to know if this was true in our own hospital.

We performed a retrospective review of 1367 nulliparous women who had reached 41+0 weeks undelivered with a live, singleton, fetus with a cephalic presentation. The women comprised two non-randomized contemporaneous cohorts: in one group, expectant management was planned, and in the second group the intention was to induce labour at 41 weeks. The primary outcome measure was the rate of CS in each group.

Of 645 women in whom expectant management was planned, 17.7% delivered by CS. Of 722 women in whom induction of labour was planned, 21.3% delivered by CS (P = 0.09). Of the total of 907 women in whom expectant management was planned or who laboured spontaneously before planned induction could be carried out, 16.6% delivered by CS. Of 460 women in whom induction was planned and actually carried out, 25.4% delivered by CS (P = 0.001).

The contention that routine induction of labour at 41 weeks reduces a woman's chance of delivery by Caesarean section was not supported by the findings of our study. Inducing labour may actually increase the nulliparous woman's risk of delivery by CS.