Mode of delivery and risk of respiratory diseases in newborns.

OBJECTIVE

To determine whether there is an increased incidence of persistent pulmonary hypertension in neonates delivered by cesarean, with or without labor, compared with those delivered vaginally.

METHODS

We did a computerized retrospective review of 29,669 consecutive deliveries over 7 years (1992-1999). The incidences of persistent pulmonary hypertension of the newborn, transient tachypnea of the newborn, and respiratory distress syndrome (RDS) were tabulated for each delivery mode. Cases of persistent pulmonary hypertension were reviewed individually to determine delivery method and whether labor had occurred. The three groups defined were all cesarean deliveries, all elective cesareans, and all vaginal deliveries.

RESULTS

Among 4301 cesareans done, 17 neonates had persistent pulmonary hypertension (four per 1000 live births). Among 1889 elective cesarean deliveries, seven neonates had persistent pulmonary hypertension (3.7 per 1000 live births). Among 21,017 vaginal deliveries, 17 neonates had persistent pulmonary hypertension (0.8 per 1000 live births). chi2 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 newborn was approximately 0.37% among neonates delivered by elective cesarean, almost fivefold higher than those delivered vaginally. The findings have implications for informed consent before cesarean and increased surveillance of neonates after cesarean.