Role of Fetal Pulmonary Artery Doppler in predicting risk of neonatal respiratory distress syndrome

Abstract

INTRODUCTION- To determine the optimal time to safely deliver a baby prematurely due to various clinical situations, it is crucial to accurately assess fetal lung maturity. Sonography which is a non-invasive technique for evaluating fetal lung maturity can be useful in predicting risk for developing neonatal respiratory distress as compared to amniocentesis which is an invasive procedure with associated risks. AIM - Purpose of this study was to determine if fetal main pulmonary artery doppler can play a role in predicting the risk of developing respiratory distress syndrome in neonates. MATERIAL AND METHODS – The participants in this prospective cross-sectional study were 75 pregnant women with gestational ages ranging from 34weeks to 36 weeks +6 days. Ultrasound doppler examination was conducted and peak systolic velocity (PSV), Systolic /Diastolic ratio, pulsatility index, resistive index were measured and acceleration time/ejection time ratio was calculated for the fetal main pulmonary artery. Diagnostic accuracy of these values was tested for predicting neonatal respiratory distress. RESULT - Of the 75 fetuses included in the study, 15 (20%) showed some signs of neonatal respiratory distress syndrome (RDS). The Acceleration time/Ejection time (AT/ET) ratio in fetal pulmonary artery correlated significantly with development of respiratory distress syndrome in neonates (P=0.001). Fetuses with respiratory distress syndrome had higher Pulsatility Index and Resistive Index values, while their AT/ET ratio was low. AT/ET was found to predict respiratory distress development with a cutoff value of 0.30 (sensitivity: 98.3 percent; specificity: 86.67 percent). Pulsatility Index and Resistive Index displayed lower sensitivity and specificity than AT/ET ratio. CONCLUSION- The fetal main pulmonary artery AT/ET ratio has a high sensitivity and specificity for predicting the development of neonatal respiratory distress syndrome. Thus, we recommend that a fetus with an AT/ET ratio of <0.30 be delivered in a facility with good neonatal care.