1. ESTROGENS HAVE BEEN REPORTED TO INCREASE THE RISK OF ENDOMETRIAL
CARCINOMA IN POSTMENOPAUSAL WOMEN.
Close clinical surveillance of all women taking estrogens is important.
Adequate diagnostic measures, including endometrial sampling when
indicated, should be undertaken to rule out malignancy in all cases
of undiagnosed persistent or recurring abnormal vaginal bleeding.
There is no evidence that "natural'' estrogens are more or
less hazardous than ''synthetic'' estrogens at equiestrogenic doses.
2. ESTROGENS SHOULD NOT BE USED DURING PREGNANCY.
There is no indication for estrogen therapy during pregnancy or
during the immediate postpartum period. Estrogens are ineffective
for the prevention or treatment of threatened or habitual abortion.
Estrogens are not indicated for the prevention of postpartum breast
Estrogen therapy during pregnancy is associated with an increased
risk of congenital defects in the reproductive organs of the fetus,
and possibly other birth defects. Studies of women who received
diethylstilbestrol (DES) during pregnancy have shown that female
offspring have an increased risk of vaginal adenosis, squamous cell
dysplasia of the uterine cervix, and clear cell vaginal cancer later
in life; male offspring have an increased risk of urogenital abnormalities
and possibly testicular cancer later in life. The 1985 DES Task
Force concluded that use of DES during pregnancy is associated with
a subsequent increased risk of breast cancer in the mothers, although
a causal relationship remains unproven and the observed level of
excess risk is similar to that for a number of other breast cancer