OC01.01: Maternal hyperoxygenation test in fetuses with congenital diaphragmatic hernia as a predictor of neonatal outcome

Objective: To predict neonatal outcome and unresponsive pulmonary hypertension (PHT) in fetuses with isolated congenital diaphragmatic hernia (iCDH) by fetal pulmonary arterial reactivity after maternal hyperoxygenation. Methods: 59 fetuses with iCDH were assessed ≥ 30 wks, either expectantly managed (n=27) or following removal of tracheal occlusion (n=32). Doppler measurements of pulsatility index (PI) in the 1st branch of the contralateral pulmonary artery were performed before and after maternal administration of 60% O2 by mask. Outcome measures included the decrease in PI after O2 (deltaPI), observed/expected lung-to-head-ratio (O/E LHR), neonatal survival at discharge, and unresponsive PHT, defined on the presence of a pre-/postductal O2 saturation gradient of > 20mmHg that did not respond to therapy. Results: Oxygen test was performed at 33.6 ± 1.6. Delivery took place at 37.1 ± 2.1 wks. In 25% we could not obtain echocardiography data, hence not assess severity of PHT. 36 (61%) neonates survived until discharge. Their O/E LHR and deltaPI values where significantly different from those who died. Only one of the survivors (2%) and 20/23 (87%) of those who eventually died after birth had unresponsive PHT, with different O/E LHR and delta PI as compared to those without or responsive PHT. Discriminant analysis shows that both prenatal measurements independently predict outcome. Conclusion: O/E LHR and Delta PI in the third trimester are both predictive parameters for neonatal survival and occurrence of severe PHT in CDH.