A recent review of the research field on body fatness and pre-eclampsia risk has added more evidence for how these two factors are linked together.
Pre-eclampsia is a serious complication of pregnancy seen as high maternal blood pressure, protein in the urine and severe fluid retention. Pre-eclampsia is the most common complication of pregnancy, affecting around five to 10 per cent of all pregnancies in Australia. One to two percent of such cases are severe enough to threaten the lives of both the mother and her unborn child.
The cause of pre-eclampsia is not known for certain, but there appears to be several factors involved. An exaggerated systemic inflammatory response, changes in immune factors, insulin resistance, and changes in the biology of the placenta are just some of a long list of candidates.
A high amount of body fat has also been linked to developing pre-eclampsia with previous research showing that pre-pregnancy weight is a strong risk factor for it recurring in subsequent pregnancies.
Now researchers have looked at 29 observational research studies that explored the link between body fatness and pre-eclampsia. From a total of almost 2 million women and over 67,000 cases of pre-eclampsia, risk of pre-eclampsia clearly rose with increasing body fatness. The risk was 58%, 168% and 212% higher for the weight categories of overweight, obese and severely obese respectively.
Even when adjustments were made for other known risk factors for pre-eclampsia, the magnitude of the risk of pre-eclampsia with higher body weights was mostly unchanged.
It made no difference if women were undergoing their first pregnancy or had several before – the connection between body fatness and pre-eclampsia was the same.
What it all means
Few options exist for lowering a woman's risk of developing pre-eclampsia. For women who are planning on becoming pregnant and are carrying a few extra kilos, losing weight may be the most realistic measure to meaningfully lower their risk.
Confused about the mixed soup of nutrition messages being stirred through the media? Tim maintains an active nutrition blog at www.thinkingnutrition.com.au where you'll find the latest nutrition research and controversies discussed in straight forward language, distilling out what you need to know for your better health.