Review supports use of ‘precautionary principle’ in new alcohol in pregnancy guidelines

A review of existing studies on the effects of low-to-moderate alcohol consumption during pregnancy has found that there is a lack of evidence to inform the new guidelines for expectant mothers about the effects of light drinking in pregnancy. The review, carried out by NIHR CLAHRC West and the MRC Integrative Epidemiology Unit, found that what little evidence does exist is poor quality.

This important public health question, of how much alcohol is actually ‘safe’ to consume during pregnancy, has been reviewed as part of the recently revised UK alcohol guidelines, published in January 2016. Light drinking was defined in the previous guidance from 2012 as four UK units of alcohol a week or less. The guidelines development group, commissioned by the UK Chief Medical Officer to develop the new national guidelines, have adopted the ‘precautionary principle’, which means that, in the light of a lack of evidence either way, people should exercise caution and avoid alcohol during pregnancy.

Our review findings support this cautious approach. We found very little evidence to support firm recommendations related to light drinking. The new guidance could advise abstention as a precautionary principle, but should explain the lack of evidence available on this topic.

It is vital that clinicians and health professionals understand these issues, and are able to answer questions from expectant women and inform them of the uncertainties in this area.