Pre-eclampsia statistics

Accurate pre-eclampsia statistics are difficult to obtain because the condition ranges from extremely mild to severe. Mild cases are sometimes not included in official figures. Furthermore, mild cases may have no effect on pregnancy, which is why the figures for pre-eclampsia as a whole are higher than for those that actually complicate pregnancies.

Around 10% of pregnant women develop pregnancy-induced hypertension (high blood pressure) or pre-eclampsia (high blood pressure with protein in the urine).¹
Worldwide more than four million women per year will develop pre-eclampsia.²
Every year in the UK pre-eclampsia is responsible for the deaths of 6–9 mothers on average, and up to as many as 1,000 babies.^3,4
10–15% of women having their first baby will develop pre-eclampsia.⁵
In one study, 47% of women who had severe pre-eclampsia in their first pregnancy experienced it again in their second pregnancy. This compared to a 7.6% risk for women who did not get pre-eclampsia in their first pregnancy.⁶
In the USA, the rate of pre-eclampsia during pregnancy increased by 25% between 1987 and 2004, to a rate of 29.4 cases per 1000 deliveries.⁷
Pre-eclampsia is responsible for up to 12% of infants born small-for-gestational-age.⁸
Pre-eclampsia is responsible for 15% of all preterm births. Infants of mothers with pre-eclampsia have a five times higher risk of dying than those of mothers without pre-eclampsia, mainly because of preterm birth.⁹

Sources:
1. Royal College of Obstetricians and Gynaecologists. Treating and preventing eclampsia - new figures released. BJOG press release, 12 September 2007. (http://www.rcog.org.uk/news/treating-and-preventing-eclampsia-new-figures-released)
2. Royal College of Obstetricians and Gynaecologists. Pre-eclampsia – Study Group Consensus Statement. 1 September 2003. (http://www.rcog.org.uk/womens-health/clinical-guidance/pre-eclampsia-study-group-consensus-statement)
3. NHS Direct Wales Encyclopaedia. Pre-eclampsia. (http://www.rcog.org.uk/womens-health/clinical-guidance/pre-eclampsia-study-group-consensus-statement)
4. Confidential Enquiry into Maternal and Child Health. Saving Mothers’ Lives: Reviewing Maternal Deaths to Make Motherhood Safer – 2003–2005. The Seventh Report of the Confidential Enquiries into Maternal Deaths in the United Kingdom. London: CEMACH; 2007. (http://www.cmace.org.uk/getattachment/927cf18a-735a-47a0-9200-cdea103781c7/Saving-Mothers--Lives-2003-2005_full.aspx)
5. Department of Health. Why Mothers Die. Report on Confidential Enquiries Into Maternal Deaths in the UK 1994-96. London: Stationery Office; 1999.
6. Sibai BM, et al. Severe preeclampsia-eclampsia in young primigravid women: subsequent pregnancy outcome and remote prognosis. American Journal of Obstetrics and Gynecology 1986;155(5):1011–16.
7. Wallis AB,et al. Secular trends in the rates of preeclampsia, eclampsia, and gestational hypertension, United States, 1987–2004. American Journal of Hypertension 2008;21(5):521–6.
8. Duley L. The global impact of pre-eclampsia and eclampsia. Seminars in Perinatology 2009;33(3):130–7.
9. Lain K, Roberts JM. Contemporary concepts of the pathogenesis and management of preeclampsia. JAMA 2002;287:3183–6.