Folic acid supplements, dietary folate and preeclampsia risk in pregnant women
What it found
Women who took folic acid supplements during pregnancy had a lower chance of developing preeclampsia.
Higher folate from food was linked to less severe preeclampsia.
What they found
Studies in people
Supplements and overall risk
Women who took folic acid supplements had a lower chance of getting preeclampsia compared with those who did not take them. This link was seen whether they started taking supplements before pregnancy or only during pregnancy.
Longer supplement use
Among women who took folic acid only during pregnancy, those who used it for a longer time had an even lower chance of preeclampsia.
Mild versus severe cases
Folic acid supplements were linked to a lower chance of mild preeclampsia. The link with severe preeclampsia was similar in size but was not statistically clear.
Folate from food
Eating more folate-rich foods during pregnancy was linked to a lower chance of severe preeclampsia. Women eating the most folate had about half the chance of severe preeclampsia compared with those eating the least. Food folate was not linked to mild preeclampsia.
Early versus late onset
The lower chance of preeclampsia linked to folic acid supplements was seen for both early and late cases. However, the link was only statistically clear for cases starting later in pregnancy.
What the authors conclude
- They suggest that taking folic acid supplements and eating more folate during pregnancy are linked to a lower chance of preeclampsia.
- They note that the amount of risk reduction may depend on how severe the preeclampsia is.
- They call for future studies to confirm these links and to find out which women benefit most from folic acid supplements.
How it was done
Preeclampsia is a serious blood pressure condition that affects 2 to 8% of first pregnancies. Scientists think folic acid might help because it lowers levels of a substance called homocysteine in the blood, which may damage the placenta.
Researchers followed 10,041 pregnant women at a hospital in Lanzhou, China, between 2010 and 2012. They asked the women about their diet and supplement use, then checked medical records for preeclampsia after delivery. Among these women, 365 developed preeclampsia.
What it can’t tell you
- Because this study followed women over time rather than randomly assigning supplements, it can show a link but cannot prove that folic acid directly prevents preeclampsia.
- Women reported their own diet and supplement use at delivery, so they may not have remembered everything perfectly.
- The study took place at one hospital in China, so the results might not apply everywhere.
Who paid
- Funding
- Funded by NICHD NIH HHS (from the PubMed record).
- Authors work at
- Gansu Provincial Maternity and Child Care Hospital, China; Yale University, USA; Shanxi Medical University, China
The paper
- Title
- Folic acid supplementation and dietary folate intake, and risk of preeclampsia
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Wang Y, Zhao N, Qiu J, et al (2015). Folic acid supplementation and dietary folate intake, and risk of preeclampsia. European journal of clinical nutrition. doi:10.1038/ejcn.2014.295Free full textPubMed 25626412DOI
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