Effect of prenatal glucocorticoid treatment on size at birth among infants born at term gestation

OBJECTIVE: To determine whether prenatal treatment with a single course of glucocorticoids (GCs) affects size at birth among full-term infants independent of fetal size before GC administration or exposure to preterm labor (PTL). STUDY DESIGN: In all, 105 full-term infants were recruited into three study groups (30 GC treated; 60 controls matched for gestational age (GA) at birth and sex; and 15 PTL controls without GC exposure). Size of the infants was estimated before treatment using two-dimensional (2D) ultrasound and by direct measurement at birth. RESULTS: Length, weight and head circumference at birth were smaller among GC-treated infants compared with matched controls (P's<0.01), although fetal size did not differ before treatment (P's>0.2). Exposure to PTL did not account for this effect. CONCLUSIONS: Prenatal treatment with a single course of GCs was associated with a reduction in size at birth among infants born at term gestation. This effect cannot be explained by differences in fetal size before treatment or exposure to PTL.