To describe the natural history of pulmonary hypertension (PH) and the risk of death and pulmonary morbidity associated with the persistence of PH through the neonatal hospitalization for these infants.

We performed a retrospective cohort study of infants with congenital diaphragmatic hernia (CDH) cared for at University of California San Francisco (2002-2012). Infants with other major anomalies or syndromes were excluded (n = 43). Clinical echocardiograms were performed weekly for up to 6 weeks or until PH resolved off respiratory support or until hospital discharge. Echocardiograms were re-read by a blinded reviewer and categorized by severity of elevation in estimated pulmonary arterial pressure. PH was defined as ≥2/3 systemic blood pressure. Severity was determined by a hierarchy of ductus arteriosus level shunt, interventricular septal position, and tricuspid regurgitant jet velocity.

Of 140 infants with ≥1 echo, 98 resolved their PH prior to death/discharge. Mean time to resolution was 18 days (median 14 days, IQR 8, 21 days). Those with persistence of PH had a higher rate of extracorporeal membrane oxygenation (P < .001) and death (P < .001), and fewer ventilator-free days (P < .001). Persistence of PH at 14 days predicted mortality (area under the receiver operating characteristic curve 0.87) and adverse respiratory outcomes (area under the receiver operating characteristic curve 0.80-0.83).

The majority of infants with CDH resolve PH between 1 and 3 weeks of life. At 2 weeks of age, severity of PH by echocardiogram strongly predicts short-term pulmonary morbidity and death. Further evaluation of physiological alterations during that time may lead to novel therapies for severe CDH.