Adverse Effects of Estrogen

ADVERSE EFFECTS

Most of the adverse effects of estrogens are described with oral contraceptives and with HRT.

In addition, dose dependent adverse effects noted when use is made for other indications are—

Ø Suppression of libido, gynaecomastia and feminization when given to males.

Ø Fusion of epiphyses and reduction of adult stature when given to children.

Ø Stilbestrol given to pregnant women, especially during first trimester (as test of pregnancy or otherwise)—increased the incidence of vaginal and cervical carcinoma in the female offspring in childhood or early adulthood. Other genital abnormalities are possible in the female as well as male offspring. Estrogens are contraindicated during pregnancy.

Ø In postmenopausal women, estrogens can increase the risk of irregular bleeding and endometrial carcinoma (5–15 fold). A progestin given concurrently blocks the risk.

Ø Estrogens can accelerate the growth of existing breast cancer, but lowdose estrogen only HRT does not appear to increase the risk of developing new breast cancer.

Ø Long-term estrogen therapy doubles the incidence of gallstones. Benign hepatomas are more common in women taking estrogens in their teens and twentys.

Ø Migraine, epilepsy and endometriosis may be worsened by estrogens.