Female gonadal function before and after treatment of acromegaly

The menstrual cycle is often abnormal in women with acromegaly. Gonadotropin deficiency may be due to a tumor mass effect (macroadenomas) and/or hyperprolactinemia and/or GH excess.

The aim of the study was to analyze the causes of ovarian dysfunction in a large series of patients with acromegaly followed up in a single center.

Gonadal function was assessed on the basis of menstrual status and hormone assays before and after treatment of acromegaly, between 1985 and 2005, in 55 patients aged from 17 to less than 45 yr.

Seventeen women (31%) were considered to be eugonadal because they had regular menstrual cycles and/or conceived spontaneously. The remaining 38 women had anovulatory cycles. Of these, 11 had hyperprolactinemia and six had hypogonadism due to a mass effect. The cause of the menstrual disturbances was mixed or unclassifiable in 14 cases. In the seven remaining cases, the gonadal dysfunction was likely related to the GH/IGF-I excess, which exerts a direct effect on the gonadotropic axis. Two had polycystic ovary syndrome, which disappeared after normalization of serum GH/IGF-I levels, suggesting that GH/IGF-I excess may also have a direct effect on the ovary. Thirty-eight women became pregnant, and all had healthy children, despite active acromegaly in 12 cases (31%).

Gonadal dysfunction is very common in premenopausal women with acromegaly. The potential causes include the lactogenic effect of prolactin, GH, or both on gonadotropic axis. Tumor mass effect or direct effect of GH or IGF-I on the ovary may also participate in ovarian dysfunction.