BackgroundThe objective of this study was to assess the risk of emergency cesarean deliveries (CDs) and adverse neonatal/maternal outcomes according to the planned gestational age at delivery (GAD) for elective CD.MethodsThe study population consisted of term singleton pregnant women who were booked for elective CD and were subsequently delivered at term by CD, after excluding cases with a trial of labor. The relationship between the planned GAD, risk of emergency CD prior to planned date, and adverse neonatal/maternal outcomes were determined.ResultsThe frequency of emergency CD, adverse neonatal and maternal outcomes were 9.5%, 4.5%, and 5.9%, respectively. The risk of emergency CD prior to the planned delivery date increased significantly according to the planned GAD (5.8% at 37 weeks, 8.2% at 38 weeks, 13.6% at 39 weeks, and 26.7% at 40 weeks or more of planned GAD, P = 0.005). Emergency CD was associated with an increased risk of adverse maternal outcomes, whereas the risk of adverse neonatal outcomes did not differ. In the total study population including both cases with elective and emergency CD, the risk of adverse maternal outcomes did not increase according to the planned GAD, and the risk of adverse neonatal outcomes decreased significantly according to the planned GAD.ConclusionThe risk of emergency CD increased as the planned GAD increased, but the risk of adverse maternal outcomes did not increase and the risk of adverse neonatal outcomes decreased significantly according to the planned GAD in the total study population including elective/emergency CD.