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High dose folic acid does not prevent pre-eclampsia in high risk women

High-dose folic acid supplements do not prevent pre-eclampsia in women at high risk for the condition, according to a new study.

Researchers from six countries looked at the prevalence of pre-eclampsia in pregnant women - beyond the first trimester – who were taking 4mg folic acid supplements compared with those who were not, but found no difference.

Just under 15% of women in the folic acid group experienced pre-eclampsia (169/1,144), compared to just under 14% (156/1,157) in the placebo group.

The researchers analysed nearly 2,500 pregnant women from across 70 obstetrical centres in five countries - Argentina, Australia, Canada, Jamaica, and the UK – all of whom had at least one high risk factor for pre-eclampsia between 2011 and 2015.

The researchers concluded: ‘Supplementation with 4.0mg per day folic acid beyond the first trimester does not prevent pre-eclampsia in women at high risk for this condition.’

They added: ‘However, folic acid supplementation remains indicated in preconception and early pregnancy but there is a need to define when to discontinue supplementation as current clinical practice guidelines do not provide clear guidance beyond the first trimester.’

In June, researchers conducting a separate study found there is no evidence that vitamin D reduces the likelihood of gestational diabetes and preeclampsia.

They said their findings supported the World Health Organization's position that 'evidence recommending vitamin D supplementation for women during pregnancy to reduce adverse pregnancy outcomes is insufficient'.

BMJ 2018, online 12 Sep