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. Journal of Perinatology (2009) 29, 731-737; doi:10.1038/jp.2009.85; published online 9 July 2009