Preconception Cardiometabolic risk factors differs for preeclampsia and gestational hypertension.

It is estimated that ten million women develop preeclampsia each year around the world, with 76,000 deaths due preeclampsia and related hypertensive disorders.  It is also responsible for 50,000 stillbirths and early neonatal deaths in developing nations.

A woman in developing country is seven times more likely to develop preeclampsia than a woman in a developed country, contributing to 10-25% of all Maternal mortality.

In the United States it affects 5-8% of all pregnancies.

According to the World Health Organization, among women who have had preeclampsia, about 20% to 40% of their daughters and 11% to 37% of their sisters also will get the disorder.

Establishing casualty, early detection and prevention of preeclampsia along with identifying the women at risk has been the mainstay of preeclampsia research in the last decade.

Preconception maternal risks for cardiovascular disease, maternal insulin resistance and diabetes in their ability to predict preeclampsia have been the subject of speculation since long. Only two studies have so far evaluated these risk factors, but their small sample size lead to discrepancy.

A recent study published April 25, 2016 in Hypertension, by Norwegian researchers evaluated the extent of similarities and differences in preconception cardiometabolic risk factors associated with gestational hypertension, preeclampsia, and preterm preeclampsia. 

It was a prospective cohort study that followed participants by linking Cohort Norway (CONOR) health surveys (1994–2003) to the Medical Birth Registry of Norway for births subsequent to CONOR participation (through to December 31, 2012).

The study confirms that pregnancy is a stressor and unmasks predisposing familial and modifiable cardiometabolic risk factors. More risk factors predicted the development of preeclampsia than gestational hypertension. Study results show that:

• A family history of diabetes mellitus and women’s preconception diabetes mellitus predicted both gestational hypertension and preeclampsia.
• A family history of myocardial infarction before 60 years of age predicted preeclampsia, but not gestational hypertension.
• A family history of stroke predicted the combined outcome of gestational hypertension or preeclampsia.
• BMI and preexisting hypertension predicted both.
• A high total cholesterol/HDL cholesterol ratio predicted both gestational hypertension and preeclampsia. In contrast, an elevated triglyceride level only predicted preeclampsia.
• Alcohol once a week as compared to none or less than one serving per month was associated with lower risks of preeclampsia in contrast to binge drinking, a strong predisposing factor for preeclampsia.
• Physical exercise 3 hours a week or more was protective for preeclampsia, but not for gestational hypertension. The protective mechanism goes beyond simple weight management and also includes reduced inflammation and oxidative stress, improved endothelial function, placental growth and vascular development.

Odds of developing gestational HT and preeclampsia according to risk factors 

These findings have important implications in preventive medicine, as it is seen that if a woman can bring down her BMI pre pregnancy than she has pretty much good chances of being protected from preeclampsia and gestational hypertension.

These results are intriguing because it could help us preventing the long term cardiovascular morbidities of preeclampsia.

So,to conclude gestational hypertension and preeclampsia have several common baseline risk factors: a family history of diabetes mellitus, preconception diabetes mellitus, hypertension, obesity, a high total cholesterol/HDL cholesterol ratio, and a family history of stroke. But, preeclampsia additionally was also predicted by a family history of myocardial infarction before 60 years of age, physical inactivity, an elevated triglyceride level, and binge drinking.

References:

Grace Egeland, Kari Klungsoyr, Nina Oyen, et al. Preconception cardiovascular risk factor differences between gestational hypertension and preeclampsia. Cohort Norway Study. Hypertension 2016; DOI:10.1161/HYPERTENSIONAHA.116.07099.

http://www.acog.org/About-ACOG/News-Room/News-Releases/2013/Ob-Gyns-Issue-Task-Force-Report-on-Hypertension-in-Pregnancy

http://www.preeclampsia.org/health-information/149-advocacy-awareness/332-preeclampsia-and-maternal-mortality-a-global-burden

https://www.nichd.nih.gov/health/topics/preeclampsia/conditioninfo/Pages/risk.aspx#f5

World Health Organization Fact Sheet, May 2012

Lim, K.-H., & Ramus, R. M. (2011). Preeclampsia. Retrieved May 02, 2016, from http://emedicine.medscape.com/article/1476919-overview