Aim To quantify the risk of neonatal respiratory morbidity for different planned modes of delivery between 35 and 38 weeks gestation.

Patients and methods Retrospective analysis of 3796 pregnancies delivered between 35+0 and 38+6 weeks gestation at a tertiary obstetric unit between 01/06/08 and 31/12/2010.

Outcome measure Admission to the neonatal unit because of respiratory morbidity.

Results For spontaneous labour, the risk of neonatal respiratory morbidity was 9.9% (16/161), 5.0% (12/238), 1.2% (5/426) and 0.64% (6/930) at 35, 36, 37 and 38 weeks gestation respectively. For induction of labour, the risk was 25% (4/16), 4.8% (5/104), 4.1% (13/318) and 0.82% (4/485) at 35, 36, 37 and 38 weeks respectively. For elective caesarean section, the risk was 13.8% (4/29), 27.1% (13/48), 4.1% (5/122) and 2.8% (9/318) at 35, 36, 37 and 38 weeks respectively. The risk of neonatal respiratory morbidity was 6.0% after elective caesarean section, 2.8% after induction of labour and 2.2% after spontaneous labour (p < 0.0001). Only 31 out of 132 (23.5%) neonates with respiratory morbidity were delivered by elective caesarean section. The overall risk of respiratory morbidity following induction of labour was 2.8% at 35-38 weeks and 5.0% at 35-37 weeks.

Conclusion Elective delivery at 35-38 weeks is associated with neonatal respiratory morbidity. Further studies are needed to evaluate the role of prophylactic corticosteroids prior to elective induction of labour.