I'm going to talk about two sets of approaches to the prevention of preeclampsia that have received a lot of attention and money invested in them over the last 15 to 20 years. These include attempts to supplement pregnant women's calcium and the use of low-dose aspirin on groups of pregnant women. The rationale in guided calcium supplementation was that hypocalcuria was recognized in women who had preeclampsia, and this suggests that there might be mechanisms responsible for the disease. In addition there were a number of reports of very high rates of preeclampsia in countries or settings where there was a low calcium intake, including lots of studies in South and Central America and in Africa.