Effect of Steroids on Arterial Doppler in Intrauterine Growth Retardation Fetuses

Abstract

Background: Antenatal steroid administration decreases fetal mortality and morbidity in preterm neonates. However, maternal steroids administration can cause a transient reduction in fetal heart rate variability and can also alter biophysical profile parameters. Other methods to assess fetal well-being in high-risk fetuses are therefore needed, when steroids are given in high-risk pregnancies. Objective: To study the effect of betamethasone and dexamethasone on placental and fetal arterial circulation in 40 growth-retarded fetuses. Methods: Forty fetuses with intrauterine growth retardation were exposed in utero to a single course of betamethasone (n = 25) or dexamethasone (n = 15). Blood flow waveforms were recorded from uterine arteries, umbilical arteries, descending aorta and middle cerebral arteries and analyzed prospectively. Doppler recordings were compared before (baseline), during (24–48 h) and after treatment (4–7 days). Results: No significant changes 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 middle 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. Conclusion: Since antenatal steroids do not seem to affect Doppler measurements, they might be useful to assess well-being in high-risk fetuses during the course. It might allow to differentiate transient iatrogenic changes in fetal heart rate variability from the effect of hypoxemia.