Neonatal morbidity after spontaneous labor onset prior to intended cesarean delivery at term: a cohort study

We aimed to investigate if labor onset before planned cesarean delivery (CD) affects the risk of neonatal admission, respiratory distress, or neonatal infectious morbidity.

Our cohort included singleton term pregnant women with intended CD who delivered at Aarhus University Hospital from 1990 to 2012. Two groups of women were identified: women with intended CD performed before labor (nonlabor CD) and women with intended CD performed after spontaneous labor onset (labor-onset CD); in both groups there was no other maternal or fetal medical indication for an immediate CD or for early-term CD scheduling. Data were stratified in early-term (37-38 weeks) and full-term (39-40 weeks) deliveries. The main outcome measures were neonatal admission, respiratory distress and neonatal infectious morbidity.

Among 103 919 live births, 5071 deliveries were nonlabor CDs and 731 were labor-onset CDs. Compared to nonlabor CD, labor-onset CD was associated with similar risks of neonatal admission and respiratory distress, both at early and full term, but with a two- to three-fold increased risk of newborn septicemia or antibiotic treatment at early term. Labor onset at early term was associated with a lower risk of maternal blood loss of more than 500 mL, but with a higher risk of postoperative antibiotic treatment and endometritis.

Labor onset before planned CD was not associated with a decrease in neonatal respiratory morbidity, but may be associated with increased risks of neonatal infection.