London - Women who take multivitamin tablets while trying to become pregnant are more at risk of having a miscarriage, research shows.
A study of 35 000 mothers-to-be found they were 32 percent more likely to lose their baby early on if they had taken the supplements regularly in the six weeks before conceiving.
Millions of women rely on the pills to boost their body’s stocks of vital vitamins and minerals and so increase their chances of having a successful pregnancy.
The researchers say in the International Journal of Epidemiology: “Women are advised to take multivitamins when they plan to conceive, believing it can do no harm.
“We found a modest but consistent increased risk of early foetal death in multivitamin users, especially in women with a regular preconceptional intake.”
They said the finding “causes concern” but were unable to explain why multivitamins raised the risk.
The NHS supplies women with multivitamin tablets after the ten-week point of their pregnancies as part of the Healthy Start scheme. They contain vitamins C, D and B9 (also known as folate), which helps protect babies from spina bifida.
Many women begin taking pills while trying to conceive. But official advice warns only against consuming too much vitamin A.
The latest study, which is the largest of its kind and focused on mothers-to-be in Denmark, was conducted by the universities of Southern Denmark, Aarhus and Pittsburgh in the US.
Taking folate supplements on their own or multivitamins while expecting had a slight beneficial effect. But the study isolated a particular risk of miscarriage among those who took the all-in-one tablets several weeks before conception, around a third of the women. Compared with taking no pills at all, regular multivitamin use for three or four weeks beforehand saw the chances of losing the baby rise by 23 percent. For the period of five to six weeks, it was 32 percent.
Although the authors couldn’t find a reason for the trend, they were able to rule out links with obesity, smoking, poverty, previous miscarriage or difficulty in conceiving.
Professor Lucilla Poston, head of the Division of Women’s Health at King’s College, London, urged women not to panic.
She said: “It is critical that the data are not interpreted as evidence against current recommendations for folate supplementation.
“The authors rightly recommend that further studies are needed. In the meantime, supplements should be taken in accordance with current clinical guidelines.” - Daily Mail