Intrapartum intervention rates and perinatal outcomes following induction of labour after 41 + 0 weeks compared to expectant management.

OBJECTIVE: There is limited evidence regarding the incidence of intrapartum fetal compromise in women who are induced compared to those managed expectantly. The aim of this study was to investigate intrapartum and perinatal outcomes in women who were induced at >41 + 0 weeks compared to an expectantly managed cohort.

METHODS: This was a retrospective cohort study of singleton, non-anomalous pregnancies delivering between 41 + 0 to 43 + 0 weeks at the Mater Mothers' Hospital, Brisbane. We compared outcomes between women who were induced and those that laboured spontaneously.

RESULTS: Six thousand five hundred and one women met the inclusion criteria. Three thousand five hundred and eighty-eight women (55.2%) underwent IOL and 2913 women (44.8%) were managed expectantly. Higher rates of emergency caesarean section (29.4% versus 18.5%, p < 0.001) and higher rates of instrumental birth (20.2% versus 17.7%, p = 0.012) were found in the IOL cohort. The odds of requiring an emergency CS for non-reassuring fetal status was increased (OR 1.51, 95% CI 1.21-1.90). Other than a high proportion of neonatal acidosis in the IOL cohort, there were no differences in perinatal outcomes between the two groups.

CONCLUSION: IOL > 41 weeks compared to expectant management results in higher rates of emergency caesarean section mainly due to intrapartum fetal compromise.