Fetal pulmonary vascular assessment and its association with postnatal ductus arteriosus flow in infants with a congenital diaphragmatic hernia

Objective To evaluate the association between fetal right pulmonary artery (RPA) parameters and postnatal ductus arteriosus velocity-time integral (DA VTI) ratios in neonates with mild or moderate left-sided congenital diaphragmatic hernia (L-CDH), and their predictive value for clinical outcomes. Methods In this prospective cohort study, 49 fetuses with mild or moderate L-CDH were evaluated between 2012-2018. RPA diameter and pulsatility index (PI) were measured at 19–24, 25–29, and 30-32 weeks gestational age (GA). Postnatal DA VTI ratios were assessed at initial echocardiography after birth. An abnormal DA VTI ratio (<1.0) served as the primary outcome. Associations between prenatal RPA parameters, postnatal DA VTI ratios, and neonatal outcomes were analyzed. Results A smaller RPA diameter at 30-32 weeks GA was associated with an abnormal DA VTI ratio (p=0.015). An RPA diameter cutoff of 2.71 mm yielded 60% sensitivity and 84% specificity (AUC=0.74, p=0.005). Neonates with abnormal DA VTI ratios had higher rates of pulmonary hypertension treatment, need for extracorporeal membrane oxygenation, and lower survival. No associations were found between prenatal RPA PI and DA VTI ratios. Conclusion In mild and moderate L-CDH, smaller RPA diameters in third-trimester associate with abnormal DA VTI ratio on initial echocardiography after birth.