Prediction of Neonatal Respiratory Distress Syndrome in Term Pregnancies by Assessment of Fetal Lung Volume and Pulmonary Artery Resistance Index

Objective: To develop reference cutoff values for mean fetal lung volume (FLV) and pulmonary artery resistance index (PA-RI) for prediction of neonatal respiratory distress syndrome (RDS) in low-risk term pregnancies.

Methods: As part of a cross-sectional study, women aged 20-35 years were enrolled and admitted to a tertiary hospital in Cairo, Egypt, for elective repeat cesarean at 37-40 weeks of pregnancy between January 1, 2012, and July 31, 2013. FLV was calculated by virtual organ computer-aided analysis, and PA-RI was measured by Doppler ultrasonography before delivery.

Results: A total of 80 women were enrolled. Neonatal RDS developed in 11 (13.8%) of the 80 newborns. Compared with neonates with RDS, healthy neonates had significantly higher FLVs (P<0.001) and lower PA-RIs (P<0.001). Neonatal RDS is less likely with FLV of at least 32 cm(3) or PA-RI less than or equal to 0.74. Combining these two measures improved the accuracy of prediction.

Conclusion: The use of either FLV or PA-RI predicted neonatal RDS. The predictive value increased when these two measures were combined.