Prenatal pulmonary hypertension index: novel prenatal predictor of severe postnatal pulmonary artery hypertension in antenatally diagnosed congenital diaphragmatic hernia

Abstract Purpose This study aim to assess the potential of prenatal predictors of postnatal severe pulmonary artery hypertension (PAH) in isolated left congenital diaphragmatic hernia (CDH) and to define a new prenatal pulmonary hypertension index (PPHI). Methods A retrospective chart review of CDH patients between May 2005 and October 2008 was conducted. Ten patients with systemic/suprasystemic and 9 patients with subsystemic pulmonary hypertension at 3 weeks of age were identified. Diameters of the right pulmonary artery, left pulmonary artery (LPAd ), aorta, and the length of vermis of the cerebellum were obtained from prenatal magnetic resonance imaging to calculate the PPHI [=(LPAd /length of vermis of the cerebellum) × 10] and the modified McGoon index (MGI) [=(diameter of the right pulmonary artery + LPAd )/diameter of aorta]. Prenatal pulmonary hypertension index and MGI were compared with lung-to-head ratio, percent predicted lung volume, and total lung volume for pulmonary hypertension and survival. Results The PPHI and MGI had a significant, negative correlation with pulmonary hypertension ( r = −0.61, P = .005, and r = −0.72, P < .005, respectively). The PPHI and MGI are significantly lower in the systemic/suprasystemic PAH group compared with the subsystemic PAH group (1.11 ± 0.32 versus 1.63 ± 0.28, P = .004, and 0.71 ± 0.15 versus 1.05 ± 0.11, P < .001, respectively). There were no significant differences between the groups comparing the lung-to-head ratio, percent predicted lung volume, and total lung volume. Conclusion Both PPHI and MGI accurately predict the severity of postnatal PAH in isolated left CDH.