Fetal hemodynamic changes following maternal betamethasone administration in pregnancies with fetal growth restriction and absent end-diastolic flow in the umbilical artery.

Objectives: To examine the effects of betamethasone administration on umbilical artery (UA), middle cerebral artery (MCA) and ductus venosus (DV) Doppler flow.

Design: Longitudinal prospective study.

Setting: Fetal Surveillance Unit, Department of Obstetrics and Gynecology, University of São Paulo, São Paulo, Brazil.

Population: Thirty-two singleton pregnancies complicated by fetal growth restriction with absent end-diastolic flow in the UA.

Methods: Pulsatility index (PI) of the UA, MCA and DV was measured from 26 to 34 weeks prior to and within 24 or 48 hours after starting betamethasone treatment course. Analysis of variance for repeated measures was used to determine the changes in the fetal hemodynamic Doppler flow following maternal corticosteroid administration.

Main Outcome Measures: Improvement of UA-PI within 24 hours and DV-PIV (venous pulsatility) within 48 hours from the first betamethasone dose.

Results: Mean gestational age at delivery was 29.3 (+/-1.8) weeks and birthweight was 806.6 (+/-228.2) g. A reduction in the UA-PI was observed in 29 (90.6%) cases, with return of end-diastolic flow in 22 (68.7%). The mean UA-PI were 2.84 (+/-0.52) before corticosteroid administration, 2.07 (+/-0.56) within 24 hours and 2.42 (+/-0.75) after 48 hours, with a significant difference along the evaluations (p<0.001). No significant changes in the MCA Doppler were observed. DV-PIV decreased from 1.06 (+/-0.23) prior corticosteroids administration to 0.73 (+/-0.16) within 24 hours and 0.70 (+/-0.19) after 48 hours (p<0.001).

Conclusions: There was reduction in the umbilical artery and in the DV pulsatility indices within 24 hours from betamethasone administration that was maintained up to 48 hours.