Background: The optimal gestational age for a planned high-order cesarean delivery (CD) reflects the balance between the risk of neonatal morbidity and the risk of unscheduled cesarean delivery prior to the scheduled date.
Methods: A retrospective cohort study of 656 women with ≥2 previous CDs were divided in two groups of women based on the gestational age at which the CD was scheduled: "38 group" and "39 group". Medical records were reviewed for demographic, medical and obstetrical history, and for adverse maternal and neonatal outcomes.
Results: The rate of unscheduled CDs was significantly higher among the 39 group (23.2% vs. 12.7%). There were no significant differences in the rate of maternal or neonatal composite adverse outcome between the two groups. The rate of neonatal respiratory morbidity, however, was higher among the 38 group (5.8% vs. 2.1%).Compared with planned CD, unscheduled CD was associated with a similar rate of maternal composite adverse outcome, but with increased rate of neonatal composite adverse outcome (23.3% vs. 8%, respectively). In a multivariable logistic regression analysis we found that this latter association was due to the earlier actual gestational age at delivery in cases of unscheduled versus planned CD.
Conclusions: Planned CD at 39 weeks, rather than at 38 weeks, is associated with more unscheduled CDs, a similar rate of maternal and neonatal composite morbidity, but a decreased rate of neonatal respiratory morbidity.
Keywords: Cesarean delivery; planned; timing; unscheduled.