Integrating fetal pulmonary artery doppler with 2D lung volumetry to predict neonatal respiratory distress

Abstract Objectives This study aims to evaluate fetal lung development through volumetric measurements and Doppler assessments of the main pulmonary artery, thereby correlating these findings with neonatal respiratory distress and Apgar score. Patients and methods The study recruited 170 healthy third-trimester pregnant women, excluding those with multiple pregnancies (twins or higher-order), chronic maternal illnesses (e.g., hypertension, diabetes, cardiac disease), fetal congenital anomalies, or maternal substance abuse. Ultrasound was used to measure fetal lung volumes (via Moeglin’s and Araujo’s formulas) and pulmonary artery Doppler indices, which were then correlated with neonatal respiratory distress and Apgar scores. Results Out of 169 pregnancies, neonatal RDS occurred in 12.4%, with incidence decreasing at higher gestational ages. Fetal lung volume predicted RDS, with Moeglin’s formula offering higher specificity (77%) and Araujo’s higher sensitivity (95.2%). Doppler parameters, specifically AT and ET, were shorter in RDS cases and provided fair predictive accuracy, which improved when combined with lung volume. Multivariate analysis identified low estimated fetal weight and reduced lung volume as independent predictors, while right lung width negatively correlated with outcomes and with both PI and AT, indicating a relationship with pulmonary vascular resistance. Conclusion Combining fetal pulmonary artery Doppler indices with 2D ultrasound lung volume measurements improves prediction of neonatal respiratory distress. Estimated fetal weight and lung volume were confirmed as independent predictors, emphasizing the value of integrating functional and structural assessments for better early risk identification in prenatal care.