Researchers at the Columbia University Mailman School of Public Health and Columbia University Medical Center report that rates of pre-eclampsia rose from 3.4 percent in 1980 to 3.8 percent in 2010. This increase was due to the rise in rates of severe pre-eclampsia – from 0.3 percent in 1980 to 1.4 percent in 2010, a relative increase of 322 percent. At the same time, rates of mild pre-eclampsia declined, from 3.1 percent in 1980 to 2.5 percent in 2010. Pre-eclampsia, which causes complications in approximately three to six percent of all pregnancies is characterized by an elevation in the blood pressure and excess protein in the urine of pregnant women. It is also associated with high risks of preterm delivery, intrauterine growth restriction, placental abruption, and perinatal mortality. The condition has a 1.5-fold to two-fold higher incidence in first pregnancies. Findings are published online in the British Medical Journal.