Synthetic corticosteroids have been successfully employed for morethan 20 years to enhance fetal lung maturity in saturations where pretermdelivery is anticipated. Dexamethasone causes a profound and transientsuppression of fetal breathing, limb and trunk movements, resulting indecreased biophysical profile scores.Biophysical profile scores werealso decreased in more than one third of fetuses within 48 hours of itsadministration.No significant changes were noted in the mean valuesof the resistive and pulsatility indices or maximal velocity flow inneither umbilical nor middle cerebral arteries.Awareness of this druginducedeffect might prevent unnecessary iatrogenic delivery of preterm fetuses.