The occurrence of pregnancy in the face of untreated Cushing syndrome is rare because of the high incidence of ovulatory disturbances experienced by patients with the disorder. A total of 58 patients with 65 pregnancies has been reported in the literature to date. Although pituitarydependent adrenal hyperplasia is the most common etiology of Cushing syndrome in the general population, adrenal adenoma is more common in the pregnant population. Significant maternal morbidity is attributable to hypertension, congestive heart failure, and poor tissue healing. Prematurity and intrauterine growth retardation account for most of the perinatal morbidity; perinatal mortality is substantial. Treatment directed at relieving hypercortisolism has been instituted during pregnancy: Pituitary or adrenal surgery, chemotherapy, and pituitary irradiation have all been reported, with variable results. Information is lacking on any alteration of maternal morbidity after treatment. The impact of therapy on perinatal outcome appears limited to a reduction in the prematurity rate, but overall numbers are small and such a conclusion should be viewed with caution. No significant maternal or perinatal complications second-ary to treatment itself were reported.