Background: Accurate evaluation of fetal lung maturity is of utmost importance for determining the optimal time for pregnancy termination. Amniocentesis is an invasive procedure and is associated with a small but real risk to the pregnancy. So noninvasive sonographic techniques to evaluate lung maturity is most needed.
Objective: To study the role of fetal main pulmonary artery Doppler (MPA) indices in prediction of Fetal Lung Maturity (FLM) and determine a cut point of Doppler indices with high sensitivity and specificity.
Patients and Methods: Our prospective cohort study included 200 pregnant women 38 weeks fulfilling the inclusion and exclusion criteria, A number of different parameters were measured from the fetal pulmonary artery flow (FPAF) waveform (At/Et, S/D, PSV, PI and RI) for diagnosis of neonatal Respiratory Distress Syndrome (RDS) by comparing the Doppler findings with the clinical outcome.
Results: About 46 (23%) fetuses were diagnosed as RDS (+ve) and 154 (77%) fetuses were without RDS(-ve). At/Et and PSV were positively correlated, whereas PI and RI were inversely correlated with RDS. S/D ratio did not change significantly. The strongest correlation was found with At/Et. AT/ET was significantly lower in the RDS +ve group and cutoff point of 0.32 predicted the development of neonatal RDS with a high sensitivity specificity, and accuracy (98.0%, 92.0%, and 95.0% respectively).
Conclusion: FLM and Neonatal RDS can be predicted using the MPA At/Et with high sensitivity and specificity.