Persistent pulmonary hypertension of the newborn following elective cesarean delivery at term

To evaluate the frequency of persistent pulmonary hypertension of the newborn (PPHN) following elective cesarean at greater than 34 weeks' gestation in an academically affiliated community hospital.

Retrospective cohort study involving chart review of 300 newborns with PPHN between 1999 and 2006. Infants less than 34 weeks' or with congenital anomalies were excluded. Subjects were divided into two groups: (1) intended vaginal delivery and (2) elective cesarean.

A total of 125 neonates were included. In all, 46 were delivered vaginally, 53 by cesarean after a trial of labor, and 26 by elective cesarean. No statistically significant differences were noted between groups in birth weight, gestational age, or length of stay. The crude relative risk (RR) of PPHN in cesareans prior to labor (elective cesareans) when compared to intended vaginal deliveries was 2.0 (95% CI 1.3-3.1). The RR of PPHN in elective cesareans when compared to spontaneous labor resulting in vaginal deliveries was 3.4 (95% CI 2.1-5.5). The adjusted RRs for these outcomes comparing the same delivery groups when considering gestational age at birth (less vs. equal to or more than 37 weeks') were 2.2 (95% CI 1.4-3.4) and 3.7 (95% CI 2.3-6.1), and birth weight (less vs. equal to or more than 2500 g) were 1.9 (95% 1.3-3.0) and 3.4 (95% CI 2.1-5.5), respectively. The incidence of PPHN in the elective cesarean group was 6.9 per 1000 deliveries. The number of cesareans to be avoided to prevent one case of PPHN in this cohort was 387 (number needed to harm, 95% CI 206.8-3003.1).

Our findings include a high rate of PPHN following elective cesarean delivery, and suggest that physicians should consider this added morbidity when performing elective cesareans.