Light drinking in pregnancy – is it safe?

The dangers of heavy drinking in pregnancy are well known. A pregnant woman who drinks large amounts of alcohol is greatly increasing her chances of suffering a miscarriage, having a premature birth, and giving birth to a baby with fetal alcohol syndrome, which is a condition that causes mental and physical problems for the child.

But when it comes to light drinking, the associated risks aren’t as well defined, leading many women to wonder whether the occasional alcoholic beverage in pregnancy is OK. Now, recently released research on the matter has attempted to form a clearer answer.

A new study has been published in the medical journal BMJ Open, with research being conducted by experts from the Medical Research Council’s Integrative Epidemiology unit at the University of Bristol. The researchers carried out a meta-analysis of all the published literature looking at the effects of low-to-moderate alcohol consumption in pregnancy. Their goal was to get a better idea of how light drinking could affect the chances of various outcomes, including miscarriage, premature delivery, and giving birth to a child with a low birth weight.

Low-to-moderate alcohol consumption is defined by the NHS as consuming one to two units once or twice a week. This translates to having no more than one or two pints of low-strength lager, or no more than one or two small glasses of wine, a week.

The researchers found that there was a link between drinking small amounts of alcohol during pregnancy and an increased risk of having a baby that is small for gestational age – with light drinkers having an eight percent higher chance of having a small baby compared to those who didn’t drink (although, as noted by the study, there could have been other factors that contributed to these results). There was also a potential link found between alcohol consumption and premature birth. But there was very little evidence pointing to strong links between alcohol and any of the other negative outcomes.

Therefore, the results seem to suggest that the odd drink here and there is unlikely to cause serious health ramifications. This might serve to reassure women who have decided to drink small amounts of alcohol during pregnancy, as well as women who may have consumed small amounts before they realised they were pregnant, that it is very unlikely to harm their developing child.

However, it’s important not to misinterpret what this new study reveals. Some journalists reporting on the research have written headlines suggesting that a more relaxed approach to alcohol is now acceptable, saying that the current guidelines from the UK’s Chief Medical Officer (advising zero alcohol intake in pregnancy) cause unnecessary anxiety for expectant women if they enjoy one or two glasses of wine a week. But these headlines run the risk of being misleading, and it’s crucial to clarify precisely what the main takeaway from the University of Bristol’s study is.

While it’s true that light drinking during pregnancy is unlikely to be damaging, and women who have consumed small amounts of alcohol should be reassured of this, there still has not been enough research on the topic to come away with any clear conclusions. It’s therefore impossible to say with certainty what the safe level of alcohol consumption for pregnant women is.

The lack of available research is mentioned in the conclusion of this latest study; the authors state that despite the distinction between light drinking and total abstinence being a main point of confusion in the medical community (and therefore leading to “inconsistent guidance and advice now and in the past”) their “extensive review shows that this specific question is not being researched thoroughly enough, if at all”. The authors also add that “formulating guidance on the basis of the current evidence is challenging”.

This is almost certainly the reason why the guidelines from the UK’s Chief Medical Officer currently recommend that, in order to stay safe and keep the risk of potential complications at an absolute minimum, it’s best for pregnant women and those who are trying to conceive to abstain from drinking any alcohol at all.

The precautionary approach is further backed up by Jonathan Pearson-Stuttard, a specialist in public health and epidemiology at Imperial College London and expert contributor to My BabyManual, who states that a lack of evidence proving something is not the same as conclusive evidence:

“It is important not to confuse the absence (or paucity) of evidence with evidence of no effect and, as such, the precautionary principle, in line with the Chief Medical Officer for England’s guidelines, of abstention during pregnancy should be viewed as the safest approach,” says Dr Pearson-Stuttard.

So, the bottom line is this: the only way to be completely sure that you’re not putting your baby at risk is by not drinking alcohol at all during your pregnancy. After all, in the case of uncertainty, it’s always best to err on the side of caution, especially when the consequences could affect your health and that of your unborn child.

If you’re concerned by the topic discussed here and are confused by how much alcohol is safe for you to drink, speak to your midwife or doctor, who will be able to provide you with the guidance you need.

And if you would like more information on the subject as well as tips on how to go teetotal for the duration of your pregnancy, you can read our article on giving up alcohol during pregnancy.