Adrenal disorders in pregnancy are relatively rare, yet can lead to significant maternal and fetal morbidity. Making a diagnosis is challenging as pregnancy may alter the manifestation of disease, many signs and symptoms associated with pregnancy are also seen in adrenal disease, and the fetal-placental unit alters the maternal endocrine metabolism and hormonal feedback mechanisms. The most common cause of Cushing's syndrome in pregnancy is an adrenal adenoma, followed by pituitary etiology, adrenal carcinoma, and other exceedingly rare causes. Medical therapy of Cushing's syndrome includes metyrapone and ketoconazole, but generally surgical treatment is more effective. Exogenous corticosteroid administration is the most common cause of adrenal insufficiency, followed by the endogenous causes of ACTH or CRH secretion. Primary adrenal insufficiency is least common. A low early morning cortisol <3 mcg/dL (83 mmol/L) in the non-stressed state and in the setting of typical clinical symptoms confirms the diagnosis. In the second and third trimester cortisol rises to levels 2-3 fold above those in the non-pregnant state, therefore a baseline level of <30 mcg/dL (823 mmol/L) warrants further evaluation. ACTH stimulated normal cortisol values have been established for each trimester. Hydrocortisone, which does not cross the placenta, is the glucocorticoid treatment of choice, and fludrocortisone is used as mineralocorticoid replacement in patients with primary disease. Congenital adrenal hyperplasia is an autosomal recessive disorder; 21-hydroxylase deficiency (21OHD) is the most common form of the disease. Non-classical 21OHD is most common, followed by the salt-wasting and simple virilizing forms. The treatment of choice for pregnant women affected with CAH is hydrocortisone, and fludrocortisones is added for those with the salt-wasting form of the disease. If the fetus is at risk for classical CAH, dexamethasone treatment can be used prenatally to prevent masculinization of the genitalia in a female infant. Because dexamethasone crosses the placenta, it should not be used to treat pregnant women with CAH if the fetus is not at risk for the disease.
