Introduction

The objective of this study was to test the hypothesis that antenatal corticosteroid therapy alters fetal cardiopulmonary and uteroplacental blood flow in pregnancies.

Material and methods

Twenty-seven singleton pregnancies between 28 and 34 gestational weeks classified as at risk of preterm birth were included prospectively. We evaluated fetal main pulmonary artery (MPA), left and right pulmonary artery (PA), left myocardial performance index (Tei index), tricuspid valve (TV), umbilical artery (UmA), middle cerebral artery (MCA), and ductus venosus (DV) parameters before and 48 hours and 7 days after antenatal steroid administration.

Results

The mean age was 31 years, and the mean gestational age was 31 weeks. The UmA S/D (Systole/Diastole) ratio, PI (pulsatility index) and RI (resistive index) values, and Doppler parameters of other vessels were not different when comparing between before and after steroid administration. Except for MCA PSV (peak systolic velocity) values, the other MCA Doppler parameters (S/D, PI, RI) were all significantly decreased. The cerebroplacental ratio (CPR) and CPR percentile values decreased significantly. All tested cardiac parameters were unchanged, except MPA ejection time (ET) (p = 0.016).

Conclusions

Our data demonstrate altered fetal MCA and CPR with corticosteroid therapy. These data suggest that antenatal corticosteroid therapy has no impact on any Doppler parameters of fetal cardiopulmonary and uteroplacental blood flow in pregnancies.