Cesarean deliveries and other risks for persistent pulmonary hypertension of the newborn.

OBJECTIVES To evaluate risks for persistent pulmonary hypertension in the newborn, confirmed by echocardiography, associated with cesarean deliveries and other factors. METHODS Cohort of all deliveries >36 weeks within a period of 23 months. A nested case-control study was performed in a subset of the cohort, involving newborns admitted into neonatal intensive care unit with diagnosis of persistent pulmonary hypertension matched with normal controls, with application of questionnaires to mothers to identify risks. Logistic regression was used to calculate odds ratios. RESULTS From 9452 newborns, 8388 (88.7%) were delivered by cesarean and 1064 (11.3%) by vaginal delivery. Questionnaires were applied to 173 mothers. Infants from cesareans had a fivefold increased risk of persistent pulmonary hypertension of the newborn: 42 (0.5%) versus 1 case (0.09%) in the vaginal group (OR 5.32, p=0.027). No interactions were found between smoking, parity, arterial hypertension and labor before cesarean section and persistent pulmonary hypertension of the newborn. First minute Apgar score <7 and maternal diabetes were related to increased risk. CONCLUSION Reducing cesarean deliveries could prevent many cases of serious persistent pulmonary hypertension of the newborn.