Preeclampsia

Preeclampsia is defined by the International Society for the Study of Hypertension in Pregnancy as gestational hypertension of at least 140/90 mmHg on two separate occasions 4 or more hours apart accompanied by significant proteinuria of at least 300 mg in a 24-hour collection of urine, arising de novo after the 20th week of gestation in a previously normotensive woman and resolving completely by the 6th postpartum week. It usually occurs during the second half of pregnancy and complicates 2% to 8% of pregnancies. Some women are considered to be at higher risk of developing preeclampsia than the general female population, and some of these are listed in Table 6.1. For example, women with antiphospholipid syndrome have a risk approximately 9 times greater than that of the general population of developing preeclampsia. Preeclampsia is a major cause of maternal and perinatal mortality and morbidity worldwide, causing 15% of all direct maternal deaths in the United Kingdom and a fivefold increase in perinatal mortality with iatrogenic prematurity being the main culprit. The Confidential Enquiry into Stillbirths and Deaths in Infancy report cites one in six stillbirths as occurring in pregnancies complicated by maternal hypertension. Preeclampsia also carries implications in adult life, with offspring of affected preterm pregnancies demonstrating poor growth in childhood and an increased risk of hypertension, heart disease, and diabetes.