Official advice from health departments advise pregnant women to avoid alcohol completely, but the NHS states a small amount of alcohol can be consumed / Rex Features

Official advice for women is to avoid alcohol altogether, but the NHS states small amounts of alcohol can be consumed

The official advice from the Department of Health and the National Institute for Health and Care Excellence (Nice) states in its guidelines that women should avoid alcohol altogether during pregnancy, or that if they do choose to drink, it should be no more than one or two units of alcohol once or twice a week.

One unit equates to half a pint of ordinary strength lager or beer, or one shot of spirits measured at 25ml, or half a standard glass of wine measured at 175ml.

The US’s Centers for Disease Control and Prevention simply states that there is no known safe amount of alcohol a woman can drink during pregnancy or while trying to get pregnant however, and that it should be altogether avoided.

It does not give the recommendation for a small amount of alcohol that could be consumed on a weekly basis.

The reason that women are advised to avoid alcohol consumption while they are pregnant is because when a woman drinks during pregnancy, alcohol is passed to the foetus from the woman’s blood through the placenta.

The NHS states that a baby’s liver is one of the last organs to develop fully and doesn’t mature until the latter stages of pregnancy, meaning that a baby cannot process alcohol in the same way an adult can, and too much exposure to alcohol can seriously affect a baby’s development.

The health service advises that drinking in the first three months of pregnancy can potentially be harmful to a baby and is linked to miscarriages and birth anomalies, while drinking in the second half of pregnancy can affect the baby’s growth and development.

Nice says in its guidelines that that getting drunk or binge drinking during pregnancy, defined as the consumption of five standard drinks or 7.5 units or more on a single occasion, may be harmful to an unborn baby.

The NHS states that drinking heavily, meaning drinking more than six units of alcohol a day, throughout a pregnancy, can cause a baby to develop foetal alcohol syndrome (FAS), which can leave children with restricted growth, facial abnormalities, and learning and behaviour disorders.