Retrospective cohort study to investigate the impact of timing for term cesarean delivery on maternal and neonatal outcomes

Background: Early-term cesarean delivery (CD) increases neonatal respiratory morbidity; however, planned late-term cesarean delivery (CD) may generate urgent CD related to spontaneous onset of labor. Aims: We investigated maternal and neonatal morbidity for planned early (37/38 week) versus late-term (39/40 weeks) CD. Our primary study aim was to investigate severe maternal morbidity and general anesthesia rates according to early versus late-term CD. Our secondary study aims were to investigate the rate of urgent surgery and other measures of maternal morbidity, and neonatal morbidity, according to early versus late-term CD and according to urgent versus elective planned CD. Methods: In our retrospective, ethically approved study of planned CD we compared maternal morbidity and neonatal respiratory morbidity, for early versus late-term CD. Results: Among 370 early versus 300 late-term CD, women who delivered at late-term CD had significantly higher rates of urgent surgery 101 (33.7%) versus 85 (23.0%) at early-term, p = .002; spontaneous onset of labor 85 (28.3%) versus 67 (18.1%), p = .0002 and out-of-hours surgery 101 (33.7%) versus 64 (17.3%), p < .0001. The frequency of neonatal respiratory morbidity composite was 10 (2.7%) for early versus 1 (0.3%) for late-term CD, p = .03. Conclusions: Late-term CD was not associated with increased maternal morbidity or use of general anesthesia in our tertiary institution. Prior reports of increased neonatal respiratory morbidity at early term CD were confirmed. Of concern, late-term CD was associated with urgent and out-of-hours CD.