Respiratory morbidity benefit of awaiting onset of labor after elective cesarean section.

Respiratory morbidity in term neonates is an important complication of elective cesarean delivery. The effect of preceding labor on the incidence and severity of respiratory morbidity in two comparable groups of neonates, 107 with and 80 without labor and with no predisposing factors to respiratory morbidity, was evaluated. Transient tachypnea of the newborn accounted for the majority of cases in term neonates. Respiratory morbidity occurred less frequently in neonates delivered after the onset of labor compared with those delivered before labor (11.2 versus 30%, P less than .002). The risk of respiratory morbidity decreased 1.5 times for each week of advancing gestational age. The presence of labor significantly reduced the risk of respiratory morbidity, independently of gestational age (P less than .03), and disease was less severe in neonates born during labor. Awaiting the onset of labor appears to be beneficial in preventing respiratory morbidity in term neonates delivered by elective cesarean section.