Adrenal disorders in pregnancy.

Pregnancy is marked by alterations in a number of endocrine systems, including activation of the renin-angiotensin-aldosterone system and the hypothalamic-pituitary-adrenal axis. The placenta, the fetal adrenal glands and the liver constitute an interactive endocrine entity, known as the fetoplacental unit. In the fetoplacental unit, the fetal adrenal glands are the primary source of dehydroepiandrosterone sulphate, which is further metabolized by the fetal liver and placenta to produce a variety of oestrogens. Several disorders can affect both the fetal and maternal adrenal glands during pregnancy. The most common fetal adrenal disorder, steroid 21-hydroxylase deficiency, leads to abnormalities in sexual development and can be life threatening for the neonate. Although rare, maternal adrenal disorders are associated with considerable maternal mortality and morbidity if not promptly recognized and treated. However, diagnosis is often difficult to establish because of the endocrine changes occurring during normal pregnancies and the lack of reference values for the majority of the adrenal steroids. This Review provides an overview of adrenal steroid metabolism during pregnancy and focuses on diagnosis and treatment of the most common fetal and maternal adrenal disorders.