Further analysis of the US Nurses Health Study drew a link between
the amount of oestrogen-only HRT a woman had had and an increased
risk of stroke. Taking just 0.625 milligrams a day appeared to
increase the risk by a third, 1.25 milligrams a day by two thirds.
Women taking combined oestrogen and progestin HRT had incurred
anincreased risk but this was slightly lower than for oestrogen-only
HRT.