Association Between Fetal Pulmonary Artery Acceleration Time/Ejection Time Ratio and Postnatal Inhaled Nitric Oxide Requirement in Surviving Infants With Left-Sided Congenital Diaphragmatic Hernia.

OBJECTIVE

To evaluate whether fetal pulmonary artery (PA) measurements and PA Doppler parameters such as acceleration time/ejection time (AT/ET) ratio predict respiratory outcomes in surviving neonates with left-sided congenital diaphragmatic hernia (CDH).

METHODS

This retrospective single-center study included fetuses with left-sided CDH born between 2016 and 2024. Fetal echocardiography assessed PA Doppler parameters, including the AT/ET ratio, peak early diastolic reverse flow, and pulsatility index. Neonatal morbidity using the use of inhaled nitric oxide (iNO) was analyzed in relation to prenatal ultrasound parameters.

RESULTS

27 fetuses with left-sided CDH were analyzed, and 3 neonates died. Among 23 survivors without structural abnormalities, the fetal contralateral PA AT/ET ratio was significantly lower in the iNO group (p = 0.019) and negatively correlated with iNO duration (r = -0.57). ROC analysis showed that an AT/ET cut-off of 0.17 predicted iNO use with 63% sensitivity and 100% specificity.

CONCLUSION

In this study, the AT/ET ratio correlated with postnatal iNO use in fetuses with left-sided CDH. It can be measured non-invasively, and may be useful for risk stratification and prenatal parental counseling.