As it is associated to pregnancy, it is often unpreventable. However, based on studies of people who have had preeclampsia, the risk can be lowered with aspirin and is only given to those who have a history of it, with a recommended daily low-dose aspirin (81 milligrams) beginning after 12 weeks of pregnancy. In some populations, women who have calcium deficiency before pregnancy — and who don't get enough calcium during pregnancy through their diets — might benefit from calcium supplements to prevent preeclampsia.