INDUCTION OF LABOUR FOR POST TERM PREGNANCY - AN OBSERVATIONAL STUDY

The aim of the study was to compare the 2 management protocols for pos tterm pregnancy; elective induction of labour at 42 weeks' gestation a nd continuing the pregnancy with fetal monitoring while awaiting spont aneous labour. A retrospective observational study compared a cohort o f 360 pregnancies where labour was induced with 486 controls. All preg nancies were postterm (>294 days) by an early ultrasound scan. Inducti on of labour was achieved with either prostaglandin vaginal pessaries or gel or forewater rupture and Syntocinon infusion. The control group consisted of women with postterm pregnancies who were not induced rou tinely and who usually had twice weekly fetal assessment with cardioto cography and/or ultrasound. Women who had their labour induced differe d from those who awaited spontaneous labour. Nulliparas (OR 1.54; 95% CI 1.24-1.83) and married women (OR 1.76; 95% CI 1.45-2.06) were more likely to have their labour induced. There was no association between the type of caregiver and induction of labour. Induction of labour was associated with a reduction in the incidence of normal vaginal delive ry (OR 0.63, 95% CI 0.43-0.92) and an increased incidence of operative vaginal delivery (OR 1.46; 95% CI 1.34-2.01). There was no difference in the overall rate of Caesarean section. There was no difference in fetal or neonatal outcomes. Parity had a major influence on delivery o utcomes from a policy of induction of labour. Nulliparas in the induce d group had worse outcomes with only 43% achieving a normal vaginal de livery (OR 0.78, 95% CI 0.65-0.95). In contrast for multiparas, the in duced group had better outcomes with less Caesarean sections (OR 0.88, 95% CI 0.81-0.96). This retrospective observational study of current clinical practice shows that induction of labour for postterm pregnanc y appears to be favoured by nulliparous married women. It suggests tha t induction of labour may improve delivery outcomes for multigraves bu t has an adverse effect for nulliparas.