The objective of the study was to examine the size and growth of fetal pulmonary artery diameters in congenital diaphragmatic hernia and assess their correlation with postnatal survival and morbidity outcomes.Study designProspective antenatal echocardiographic examination of fetal branch pulmonary arteries were correlated with postnatal survival and respiratory morbidity in cases of congenital diaphragmatic hernia. Receiver operator curves were developed to assess their utilization as predictors of respiratory morbidity and survival.ResultsTwenty-one cases were diagnosed antenatally over 3 years. Fifteen subjects survived postnatally. The ipsilateral fetal branch pulmonary artery diameter was smaller throughout gestation in left-sided congenital diaphragmatic hernia (P = .008). The small left pulmonary diameter did not correlate with survival but correlated strongly with morbidity outcomes. Progressive ipsilateral fetal pulmonary artery hypoplasia was demonstrated throughout gestation in subjects who died or had severe morbidity.ConclusionFetal pulmonary artery diameter measurements correlate with respiratory morbidity in postnatal congenital diaphragmatic hernia and may assist with prediction of outcome. Survival has improved, possibly because of improved postnatal management of congenital diaphragmatic hernia, limiting this measurement in assessing survival.