Effect of prenatal betamethasone on fetal, uteroplacental, and maternal blood flow velocity in pregnancies complicated by fetal growth restriction.

OBJECTIVE: To assess Doppler flow velocity in fetal, uteroplacental, and maternal arteries before and after betamethasone therapy among singleton pregnancies complicated by fetal growth restriction (FGR).

METHODS: A prospective, longitudinal, multicenter study was conducted at three university-affiliated hospitals in Tehran, Iran, between January 1 and November 30, 2013. The inclusion criteria were FGR, a gestational age of 24-34 weeks, no fetal anomalies, and no previous betamethasone therapy. Doppler blood flow was measured in uterine, umbilical, and middle cerebral arteries before treatment, and 24 hours and 5 days after completion of betamethasone therapy (two 12-mg doses at a 24-hour interval).

RESULTS: Overall, 40 women were enrolled. Doppler blood flow through the uterine and umbilical arteries showed significant but transient changes across the three timepoints (P<0.001), whereas the middle cerebral artery showed no changes.

CONCLUSION: Prenatal betamethasone led to transient improvements in blood flow in the uterine and umbilical arteries among pregnancies affected by FGR.