Sonographic prediction of fetal main pulmonary artery (MPA) Doppler indices of lung maturity and neonatal respiratory distress syndrome (RDS) development

PURPOSE: The aim of this study is to highlight the predictive role of perinatal fetal main pulmonary artery (MPA) Doppler measurements in neonatal respiratory distress syndrome development. Respiratory distress syndrome (RDS) is one of the lead causes of neonatal respiratory distress as well as neonatal death. Thus, it seems logic to evaluate fetal lung maturity before labour. METHODS: The study is a prospective cohort study performed in tertiary hospital over a period of one-year duration. 70 pregnant ladies between 34 and 38 weeks of gestation were referred for fetal echo, when pregnancy was considered a high risk. A trained radiologist using dedicated ultrasound machine with updated obstetric and fetal echo software performed the fetal echo. Doppler mode and curvilinear probe of 5.7 MHz transducer. Pediatric neonatologist observed the neonatal outcome post-natally. RESULTS: A total of 70 pregnant patients with risk factors underwent fetal echo, 26/70 (37.1%) were diagnosed with RDS conforming to the neonatal criteria. The mean acceleration time/ejection time ratio (At/Et ratio) of the fetal pulmonary artery was significantly reduced in fetuses that subsequently developed RDS than those without RDS. Contrarily, the mean pulsatility index (PI), resistance index (RI), and peak systolic velocity (PSV) of the fetal pulmonary artery were significantly high in fetuses who later developed RDS than in those who did not. CONCLUSION: Fetal MPA Doppler measurements have a major role in anticipating the development of neonatal RDS in preterm and early term neonates.