Influence of labor and route of delivery on the frequency of respiratory morbidity in term neonates

OBJECTIVES: The purpose of this study is to compare the frequency of respiratory morbidity (RDS-Type I, RDS-Type II and PFC) in term neonates relative to three different delivery modes (cesarean delivery without labor, cesarean in labor, vaginal delivery). METHODS: A case-control study was performed consisting of 692 maternal/neonate pairs at term gestation with either a documented mature lung profile at an obstetrical age ≥37 weeks' gestation or a Dubowitz age ≥ 38 weeks' gestation. RESULTS: Overall, the frequency of neonatal respiratory morbidity was 5.1%. Neonatal respiratory morbidity was observed in 23 (12.4%) of 186 cases when cesarean delivery was performed prior to the onset of labor; in 10 (5.6%) of 177 cases when the cesarean delivery was performed after labor had ensued; and in 2 (0.6%) of 329 cases when the fetus was delivered vaginally (P < 0.001). CONCLUSION: The frequency of respiratory morbidity in term neonates is influenced by labor and route of delivery, and it is highest when cesarean delivery is performed prior to the onset of labor.