The hypercortisolemia in Cushing's syndrome is usually due to a corticotropin (ACTH)-producing pituitary tumor (Cushing's disease), ectopic ACTH secretion by a nonpituitary tumor, or cortisol secretion by an adrenal adenoma or carcinoma. There are also very rare tumors that secrete corticotropin-releasing hormone (CRH) ectopically, and occasional cases are caused by cortisol secretion by ACTH-independent macronodular or micronodular hyperplasia of the adrenal cortex. (See "Establishing the cause of Cushing's syndrome".)
This topic will review issues related to Cushing's syndrome in pregnancy. The clinical manifestations, diagnosis, and treatment of Cushing's syndrome in nonpregnant patients are discussed separately. (See "Epidemiology and clinical manifestations of Cushing's syndrome" and "Establishing the diagnosis of Cushing's syndrome" and "Overview of the treatment of Cushing's syndrome".)
CUSHING'S SYNDROME AND PREGNANCY
Cushing's syndrome is associated with a high prevalence (up to 75 percent) of ovulatory disturbances induced by cortisol excess [1,2]. As a result, women with untreated Cushing's syndrome rarely become pregnant .
The frequency of ACTH-independent cases is increased in pregnant as compared to non-pregnant individuals. Of the approximately 136 reported cases, approximately 60 percent had ACTH-independent Cushing's syndrome (48 percent adenoma and 10 percent carcinoma); most of the rest had Cushing's disease or bilateral adrenal hyperplasia [1-4]. Five pregnant women with the ectopic ACTH syndrome have been reported [1,3,5-7].
The reason for this unusual pattern is not known. Pure cortisol-secreting adrenal adenomas may interfere with reproductive function less than the mixed cortisol and androgen excess produced by adrenal carcinomas or ACTH-dependent adrenal hyperplasia. In addition, most patients with the ectopic ACTH syndrome are men .