Background: As gestational age grows, the risk of newborn respiratory distress syndrome (RDS) diminishes because the lungs are the last foetal organs to properly mature. While neonatal RDS does not just occur following preterm births, it is often thought of as a disorder of premature babies. This study sought to determine how prenatal lung capacity and foetal Pulmonary artery resistance index (PARI) affected the probability that newborn RDS would occur. Methods: This prospective observational study was carried out on 200 pregnant women aged 20-35 years, with gestational age between 36-40 weeks and singleton pregnancy. According to neonatal outcome the patients were classified into two groups: group A: 26 cases with noenatal RDS and group B: 174 cases without neonatal RDS. All patients were subjected to 2D ultrasonography and 3D ultrasonography. Results: Fetal lung volume (FLV) is a significant predictor of neonatal RDS (AUC: 0.820, p <0.001), at a cut off value of ≤35, with 88.5% sensitivity and 68.4% specificity. PARI is not a significant predictor of neonatal RDS. 1 and 5 min Apgar score were significantly lower in neonates who developed RDS and those who didn’t (p<0.001). Conclusions: 3D FLV and estimated fetal weight measurement using ultrasonography may be a reliable non-invasive indicator of the incidence of newborn RDS in preterm pregnancies when the risk of RDS progression is present. FLV is a significant predictor for neonatal RDS at a cutoff for ≤35 cm3 with sensitivity 88.5% and specificity 68.4%.