Making sense of research
14th March 2015
It’s not uncommon to read media headlines reporting ‘new information’ about the causes of miscarriage. Whether it’s low vitamin D levels, pre-pregnancy vitamins or working night-shifts, they can all make women feel blamed, that they could and should have done something to prevent their miscarriage.
It’s the Miscarriage Association’s job to get beyond the headlines, to read and analyse the research reports carefully, to discuss them with trusted advisors and then to explain what those findings mean in practice. Often it’s about explaining the difference between a link, a risk and a cause.
Here’s a good example, from January 2014.
Vitamins
In January, 2014 the Daily Mail reported results from a Danish study* which found that pregnant women were a third more likely to miscarry if they took vitamin supplements before conception. Unsurprisingly, the article immediately rang alarm bells, both for women and for some of the health professionals caring for them.
Reading the original research article clarified a few things:
First of all, the authors referred to a ‘modest’ increase in risk, specifically amongst women who took multivitamins in the 5 to 6 weeks before conception.
Second, the multivitamins they referred to were those in the most commonly used multivitamin in Denmark, which has a rather different formula from the pre-conception and pregnancy preparations on sale in the UK. One key difference is that the Danish multivitamins included Vitamin A, which is generally not recommended in pregnancy preparations.
Third, this was an association, not a cause. Even though there was a higher rate of miscarriage among the women who reported taking multivitamins before conception, it couldn’t be shown that this was the cause of their miscarriages. There might have been something else that they had in common, other than the vitamins.
Consulting with our experts, we concluded that taking a specialist pregnancy preparation is highly unlikely to be harmful and may well be helpful if for women with a poor diet. If you’d rather not take any such supplements – apart from the folic acid supplements that are recommended in pregnancy – a healthy diet with plenty of fruit and vegetables is probably the best start there is.
*Periconceptional intake of vitamins and fetal death: a cohort study on multivitamins and folate, by Ellen Nohr et al. Published in the International Journal of Epidemiology on 21 Jan 2014 (online)
