Mode of delivery and risk of respiratory diseases in newborns

Objective: To determine whether there is an increased incidence of persiste nt pulmonary hypertension in neonates delivered by cesarean, with or withou t labor, compared with those delivered vaginally. Methods: We did a computerized retrospective review of 29,669 consecutive d eliveries over 7 years (1992-1999). The incidences of persistent pulmonary hypertension of the newborn, transient tachypnea of the newborn, and respir atory distress syndrome (RDS) were tabulated for each delivery mode. Cases of persistent pulmonary hypertension were reviewed individually to determin e delivery method and whether labor had occurred. The three groups defined were all cesarean deliveries, all elective cesareans, and all vaginal deliv eries. Results: Among 4301 cesareans done, 17 neonates had persistent pulmonary hy pertension (four per 1000 live births). Among 1889 elective cesarean delive ries, seven neonates had persistent pulmonary hypertension (3.7 per 1000 li ve births). Among 21,017 vaginal deliveries, 17 neonates had persistent pul monary hypertension (0.8 per 1000 live births). chi (2) analysis showed an odds ratio 4.6 and P < .001 for comparison of elective cesarean and vaginal delivery for that outcome. Conclusion: The incidence of persistent pulmonary hypertension of the newbo rn was approximately 0.37% among neonates delivered by elective cesarean, a lmost fivefold higher than those delivered vaginally. The findings have imp lications for informed consent before cesarean and increased surveillance o f neonates after cesarean. (C) 2001 by The American College of Obstetrician s and Gynecologists.