This causes measurable changes in laboratory tests of coagulation but only minor clinical adverse events. A recent study did show that the incidence of thrombophlebitis increased with estrogen, but only during the first year of therapy. The risk was 1.3 cases per 10,000 women who didn't use estrogen and 2.6 cases per 10,000 women using estrogen. Estrogens should not be used in women with a history of coagulopathy, although a remote history of a single episode of thrombophlebitis associated with surgery, trauma or pregnancy is not a contraindication. The risk of gallstones doubles with estrogen.
Estrogens help to delay the loss of skin collagen and are therefore beneficial to the skin.
It also is used to treat vaginal atrophy. Recent preliminary epidemiological studies have suggested that there is a lower incidence of Alzheimer's disease in women who take estrogen, but this needs confirmatory studies. Contrary to popular opinion, estrogens do not cause weight gain. In fact, the PEPI study showed that women who used estrogen averaged 1.0 kg less weight gain and 1.2 cm less increase in waist girth. The overall relative risk of death in postmenopausal women who currently take estrogen is decreased to about 0.7.