Optimal timing for elective caesarean delivery in a Chinese population: a large hospital-based retrospective cohort study in Shanghai

Objective To assess the relationship between the timing of antepartum elective caesarean delivery (CD) at term and perinatal outcomes in a Chinese population. Methods We conducted a retrospective cohort study of mode of delivery at a large obstetric centre in Shanghai, China between 2007 and 2014. Eligibility criteria included: term nulliparous women with a singleton gestation undergoing antepartum elective CD. Results There were 19 939 women delivered by antepartum CD without indications, with 5.9% performed at 37-37 6/7 weeks, 36.2% at 38-38 6/7 weeks, 38.4% at 39-39 6/7 weeks, 15.4% at 40-40 6/7 weeks, 4.0% at >= 41 weeks. As compared with births at 39-39 6/7 weeks, births at 37 weeks were associated with an increased odds of neonatal respiratory disease (adjusted odds ratian(aOR): 4.82; 95% CI 3.35 to 6.94), neonatal infection (aOR: 3.68; 95% CI 1.80 to 7.52), hypoglycaemia (aOR: 3.85; 95% CI 2.29 to 6.48), hyperbilirubinaemia (aOR: 3.50; 95% CI 2.12 to 5.68), neonatal intensive care admission (aOR: 3.73; 95% CI 2.84 to 4.89) and prolonged hospitalisation (aOR: 7.51; 95% CI 5.10 to 11.07). Births at 38 weeks, 40 weeks or >= 41 weeks were also associated with an increased odds of neonatal respiratory disease with corresponding aORs (95% CI) of 2.26 (1.71 to 3.00), 1.97 (1.33 to 2.94) and 2.91 (1.80 to 4.70), respectively. Conclusion For women undergoing elective CD, neonatal outcome data suggest that delivery at 39-39 6/7 complete weeks is optimal timing in a Chinese population.