Does in utero exposure to synthetic glucocorticoids influence birthweight, head circumference and birth length? A systematic review of current evidence in humans.

Synthetic glucocorticoids are the mainstay treatment for stimulating lung maturation in threatened preterm delivery. Animal studies suggest that in utero exposure to glucocorticoids leads to a reduction in birth size. Smaller birthweight has been associated with higher risk of many chronic diseases. Therefore, the authors undertook a systematic review of human studies examining the association between synthetic glucocorticoid treatment and birth size. Medline, EMBASE, PubMed, Cochrane, Google scholar and Institute of Life Science databases were searched for studies published between 1978 and 2009 investigating the association between synthetic glucocorticoids and birthweight, head circumference, birth length and ponderal index. All studies controlling for gestational age were examined. Seventeen studies were included in the analysis. Nine out of 17 studies reported a reduction in birthweight (range 12-332 g), five of nine a reduction of head circumference (range 0.31-1.02 cm) and two of four a reduction of 0.8 cm in birth length. Despite methodological inconsistencies and limitations that impede clear conclusions, the evidence suggests an association between in utero exposure to synthetic glucocorticoids and reduced birth size.