Challenges in Prenatal Treatment with Dexamethasone

Classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency causes elevated androgen levels, which can lead to virilization of female external genitalia. Prenatal dexamethasone treatment has been shown to be effective in preventing virilization of external genitalia when started prior to 7-9 weeks of gestation in females with classic CAH. However, CAH cannot be diagnosed prenatally until the end of the first trimester. Treating pregnant women with a fetus at risk of developing classic CAH exposes a significant proportion of fetuses unnecessarily, because only 1 in 8 would benefit from treatment. Consequently, prenatal dexamethasone treatment has been met with much controversy due to the potential adverse outcomes when exposed to high-dose steroids in utero. Here, we review the short- and long-term outcomes for fetuses and pregnant women exposed to dexamethasone treatment, the ethical considerations that must be taken into account, and current practice recommendations.