Effect of steroids on arterial Doppler in intrauterine growth retardation fetuses

Background: Antenatal steroid administration decreases fetal mortality and morbidity in preterm neonates. However, maternal steroids administration ca n cause a transient reduction in fetal heart rate variability and can also alter biophysical profile parameters. Other methods to assess fetal well-be ing in high-risk fetuses are therefore needed, when steroids are given in h igh-risk pregnancies. Objective: To study the effect of betamethasone and d examethasone on placental and fetal arterial circulation in 40 growth-retar ded fetuses. Methods: Forty fetuses with intrauterine growth retardation we re exposed in utero to a single course of betamethasone (n = 25) or dexamet hasone (n = 15). Blood flow waveforms were recorded from uterine arteries, umbilical arteries, descending aorta and middle cerebral arteries and analy zed prospectively. Doppler recordings were compared before (baseline), duri ng (24-48 h) and after treatment (4-7 days). Results: No significant change s were found in the pulsatility indices (PI) in any of these vessels during the course and after the treatment was stopped. However, the PI in the mid dle cerebral arteries showed a trend to decrease 24-48 h and 4-7 days after steroids were given to the mother when compared to pretreatment values. Co nclusion: Since antenatal steroids do not seem to affect Doppler measuremen ts, they might be useful to assess well-being in high-risk fetuses during t he course. It might allow to differentiate transient iatrogenic changes in fetal heart rate variability from the effect of hypoxemia. Copyright (C) 20 00 S. Karger AG. Basel.