The role of doppler waveforms in the fetal main pulmonary artery in the prediction of neonatal respiratory distress syndrome.

Objective: To describe changes in the Doppler waveforms of the fetal main pulmonary artery (MPA) throughout gestation and to assess their predictive value of neonatal respiratory distress syndrome (RDS).

Study Design: In the first phase of this study, we performed Doppler measurement of MPA acceleration time (AT), ejection time (ET), peak systolic velocity, end-diastolic velocity, mean velocity, pulsatility index, and resistance index in 288 healthy fetuses. In the second phase, we carried out these measurements in a prospective cohort of 52 pregnant women with impending preterm birth.