Fetal Pulmonary-Artery Doppler Dynamics in Preeclampsia: Acceleration Time, Ejection Time, PAT/ET Ratio, and Prediction of Adverse Neonatal Pulmonary Outcome.

To investigate the predictive value of fetal main pulmonary artery (MPA) Doppler parameters, including acceleration time (AT) and the acceleration time-to-ejection time ratio (PAT/ET), for composite adverse pulmonary outcomes (CAPO) in pregnancies complicated by preeclampsia. This prospective case-control study included 120 singleton pregnancies (60 with preeclampsia and 60 normotensive controls) followed at Ankara Etlik City Hospital between March and June 2025. Doppler ultrasonography was performed using a Voluson E10 system. MPA Doppler waveforms were recorded in an axial or sagittal thoracic view, and PAT/ET and AT were calculated from three averaged cardiac cycles. CAPO was defined as the presence of at least one of the following: respiratory distress syndrome (RDS), transient tachypnea of the newborn (TTN), need for CPAP or mechanical ventilation, or NICU admission. The preeclampsia group exhibited significantly lower PAT/ET ratios (0.180 ± 0.09 vs 0.240 ± 0.07, P < .001) and shorter AT (44.1 ± 18.0 ms vs 57.1 ± 13.2 ms, P < .001), along with higher MPA PI and RI values. CAPO incidence was significantly higher in the preeclampsia group (31.6 vs 11.6%, P < .001). ROC analysis demonstrated that PAT/ET <0.180 predicted CAPO with 78.5% sensitivity, 63.0% specificity, and an AUC of 0.760. Similarly, AT <45.5 ms yielded 75.3% sensitivity, 63.0% specificity, and an AUC of 0.749. Fetal MPA Doppler parameters, particularly PAT/ET and AT, may serve as noninvasive predictors of neonatal respiratory morbidity in preeclamptic pregnancies. Incorporating these indices into routine antenatal surveillance could support timely perinatal interventions and improve neonatal outcomes.