Birth Outcomes for Midwifery Clients Who Begin Postdates Induction of Labour Under Midwifery Care Compared With Those Who Are Transferred to Obstetrical Care

OBJECTIVE: This study sought to compare clinical outcomes of midwifery clients who had postdates induction of labour with oxytocin under midwifery care with those transferred to obstetrical care. METHODS: This was a retrospective cohort study using 2006-2009 Ontario Midwifery Program data. All low-risk Ontario midwifery clients who had postdates oxytocin induction were included. Groups were established according to the planned care provider at onset of induction. The primary outcome was Cesarean section (CS). The secondary outcome was a composite of stillbirth, neonatal death, or serious morbidity. Other outcomes included assisted vaginal delivery, pharmaceutical pain relief, and use of episiotomy. We stratified by parity and used logistic regression to conduct analyses controlling for maternal age (Canadian Task Force Classification II-2). RESULTS: For nulliparas, postdates induction with oxytocin under midwifery care decreased the odds of interventions including assisted vaginal delivery (OR 0.68; 95% CI 0.48-0.97), episiotomy (OR 0.49; 95% CI 0.34-0.70), and pharmaceutical pain relief (OR 0.57; 95% CI 0.36-0.90), with no difference in odds of neonatal morbidity or mortality (OR 0.71; 95% CI 0.25-2.04) when compared with induction under obstetrical care. For multiparas, the use of pharmaceutical pain relief was significantly lower in the midwifery group (OR 0.65; 95% CI 0.44-0.96). CONCLUSION: For low-risk midwifery clients at 41 weeks or more gestation, the odds of Caesarean section and neonatal morbidity and mortality are similar when induction of labour with oxytocin under the care of a midwife is compared with induction of labour under obstetrical care, and rates of intervention are decreased.