Alcohol is associated with several adverse health conditions including liver disease, heart disease, stroke and cancer.1 Alcohol-related harm is a major public health issue in the UK and across the world. In 2016, alcohol was estimated to the seventh leading risk factor of all deaths across the world, accounting for approximately 5.2% of all deaths.2 This translates to more than 3 million deaths each year. In the UK, the Chief Medical Officers recommend that members of the general population consume no than 14 units of alcohol a week regularly, and if you do drink 14 units a week, it is best to spread this consumption evenly over three days or more.
Recent research has estimated alcohol use in pregnancy to be just under 10%.3 During pregnancy, alcohol reaches the growing baby through the placenta. The baby’s liver is unable to process alcohol the way an adult is able to and exposure to alcohol can affect their development in several ways. In the first trimester (three months), alcohol consumption increases the risk of miscarriage, premature birth and the baby being born with a low birth weight. Alcohol consumption later in the pregnancy can lead to other health effects in childhood such as behavioural difficulties, impaired intellectual ability and mental health conditions.4
Heavy consumption of alcohol during pregnancy can result in a specific syndrome called foetal alcohol syndrome. This condition results in babies suffering from poor growth in infancy and childhood, facial abnormalities as well as learning difficulties.4 A recent study estimated that one in every 67 women who consumed alcohol during pregnancy would deliver a child with foetal alcohol syndrome.3
Recent research which received much media interest analysed all published research on the effects of low-to-moderate levels of alcohol consumption in pregnancy on pregnancy itself and longer-tern outcomes upon the child.5 This was the most comprehensive systematic review to date on this issue and found that there are ‘surprisingly’ few research studies prospectively researching the issue of whether light maternal alcohol consumption (defined as up to 4 units per week during pregnancy) has a causal effect upon the infant’s health, additional future offspring outcomes or pregnancy outcomes. Therefore, they concluded, there is a lack of evidence demonstrating a clear detrimental effect, or a safe limit of alcohol consumption. This finding does not mean that it is safe to drink up to 4 units a week, instead, this research highlights that the evidence is not sufficient to answer the question conclusively. In light of this, current national guidelines still emphasise that the safest level of alcohol consumption during pregnancy for both mother and baby is zero.
The Chief Medical Officers of the UK countries recently updated their guidance and advise that for women who are pregnant, or those planning a pregnancy, the safest approach to alcohol is to drink no alcohol at all. This approach minimises risks to the foetus. The Chief Medical Officers assert that drinking alcohol during pregnancy can lead to long-term harm to the unborn baby, and importantly the more alcohol that is consumed during pregnancy, the greater the risk.6
There has been uncertainty in the literature regarding potential effects of alcohol consumption in men upon semen quality. The most comprehensive review to date, including more than 16,000 men, found that alcohol intake has a detrimental effect upon semen volume.7 The findings suggest that moderate consumption of alcohol did not adversely affect semen parameters compared to daily or heavy consumption. However, the evidence remains inconclusive, and further research is required to aid clinical guidance.