Q&A: Alcohol and pregnancy

Health experts have toughened up their advice to women, warning them that they should not drink at all during pregnancy.

What is the latest guidance?

The National Institute for Health and Clinical Excellence (NICE) is advising that women should not drink alcohol at all during pregnancy - and that it is particularly important not to drink in the first three months.

It says that if women feel they cannot face a teetotal pregnancy, then they should limit their alcohol intake after three months to one or two units once or twice a week.

Binge drinking - defined as more than 7.5 units of alcohol in a single session - is an absolute no-no.

The guidance, which covers England, Wales and Northern Ireland, brings NICE into line with the government in England.

Previously, draft NICE guidance had suggested that pregnant women keep their alcohol intake down to one unit of alcohol a day.

What impact does alcohol have on the unborn baby?

Alcohol can cross from the mother's blood via the placenta to the baby's circulation.

It is well established that heavy drinking during pregnancy can affect the development of the foetus.

The first three months, or first trimester, of pregnancy is particularly key, as this is the time when the organs and nervous system are rapidly developing.

Heavy alcohol consumption during the more advanced stages of pregnancy can also stymie general growth.

In particularly serious cases heavy drinking can lead to a condition known as foetal alcohol syndrome.

This a name given to a set of symptoms which can include facial abnormalities, such as small heads and widely spaced eyes, poor growth, impaired learning and memory skills and behavioural problems such as hyperactivity.

The National Organisation on Foetal Alcohol Syndrome estimates more than 6,000 UK children are born with Foetal Alcohol Spectrum Disorder each year.

Heavy drinking also significantly raises the risk of a miscarriage.

What about more moderate alcohol consumption?

Science has yet to pin down the exact impact of low levels of alcohol consumption in pregnancy.

There is currently no evidence to suggest that drinking one or two units once or twice a week - or indeed moderate drinking at slightly higher levels - has any negative impact on the developing foetus.

However, doctors stress that just because the hard evidence is not there does not mean that low-level drinking is safe.

They advise that the only 100% way to guarantee that a baby will not be affected by alcohol is to avoid it completely.

What about breastfeeding?

Doctors suggest that the occasional drink - again one to two units no more than once or twice a week - probably won't do any harm.

However, more heavy drinking can make breast milk smell different to a baby, potentially disrupting their feeding patterns.

There is also evidence that it can cause problems for a baby's digestion.

Alcohol clears from a mother's milk at the rate of around one unit every two hours. So try to avoid alcohol before breastfeeding, or plan ahead and express milk if you know you will be drinking.

How much is a unit of alcohol?

The measurement of alcohol units was recently revamped to take account of the modern trend for stronger drinks, and bigger glasses.

A half pint of normal beer and a single shot of a spirit is defined as a single unit, while a medium glass of 12.5% table wine is considered to contain two units.

BBC News