Preeclampsia and eclampsia are part of the spectrum of high blood pressure, or hypertensive, disorders that can occur during pregnancy.
At the mild end of the spectrum is gestational hypertension, which occurs when a woman who previously had normal blood pressure develops high blood pressure when she is more than 20 weeks pregnant and her blood pressure returns to normal within 12 weeks after delivery. This problem usually occurs without other symptoms. In many cases, gestational hypertension does not harm the mother or fetus. Severe gestational hypertension, however, may be associated with preterm birth and infants who are small for their age at birth.1 Up to one-fourth of women with gestational hypertension go on to develop preeclampsia.2
Preeclampsia is similar to gestational hypertension, because it also describes high blood pressure at or after 20 weeks of pregnancy in a woman whose blood pressure was normal before pregnancy. But preeclampsia can also include blood pressure at or greater than 140/90 mmHg, increased swelling, and protein in the urine.3 The condition can be serious and is a leading cause of preterm birth (before 37 weeks of pregnancy).4 If it is severe enough to affect brain function, causing seizures or coma, it is called eclampsia.
One of the serious complications of hypertensive disorders in pregnancy is HELLP syndrome, a situation in which a pregnant woman with preeclampsia or eclampsia suffers damage to the liver and blood cells. The letters in the name HELLP stand for the following problems:
- H - Hemolysis, in which oxygen-carrying red blood cells break down
- EL - Elevated Liver enzymes, showing damage to the liver
- LP - Low Platelet count, meaning that the cells responsible for stopping bleeding are low
- Roberts, J. M., Bodnar, L. M., Lain, K. Y., Hubel, C. A., Markovic, N., Ness, R. B., & Powers, R. W. (2005). Uric acid is as important as proteinuria in identifying fetal risk in women with gestational hypertension. Hypertension, 46(6), 1263–1269. Retrieved January 4, 2017, from https://www.ncbi.nlm.nih.gov/pubmed/16246973
- Saudan, P., Brown, M. A., Buddle, M. L., & Jones, M. (1998). Does gestational hypertension become pre-eclampsia? British Journal of Obstetrics and Gynaecology, 105(11), 1177–1184.
- American College of Obstetricians and Gynecologists. (2013). Hypertension in pregnancy. Washington, DC: ACOG. Retrieved December 30, 2016, from http://www.acog.org/Resources-And-Publications/Task-Force-and-Work-Group-Reports/Hypertension-in-Pregnancy
- Goldenberg, R. L., Culhane, J. F., Iams, J. D., & Romero, R. (2008). Epidemiology and causes of preterm birth. The Lancet, 371(9606), 75–84. Retrieved December 13, 2016, from http://www.thelancetnorway.com/journals/lancet/article/PIIS0140-6736(08)60074-4/fulltext