Date: January 2024, Version 3.0

Quick read

The Department of Health in the UK recommends that alcohol should be avoided for the full nine months of pregnancy and, ideally, whilst trying to conceive. This is because alcohol can cause birth defects and learning problems, and studies have not been able to show that any amount is safe.

Alcohol during pregnancy

Alcohol consumed at any stage of pregnancy can reach the baby. Babies in the womb cannot process alcohol in the same way as an adult and, as a result, alcohol remains in the baby’s body for several hours after it has been cleared from the mother’s bloodstream. 

Exposure to alcohol in the womb can cause lifelong problems with learning and behaviour, as well as some birth defects, miscarriage and stillbirth, and preterm delivery. While the strongest chance of problems has been most clearly linked to heavy drinking, studies have not been able to prove that any amount of alcohol during pregnancy is safe. Some unborn babies are likely to be affected by lower levels of alcohol than others. 

It is for these reasons that the Department of Health in the UK recommends that alcohol should be avoided for the full nine months of pregnancy and, ideally, whilst trying to conceive. If you need help to do this, you can ask your doctor or midwife for information on the support available. 

What if I have already drunk alcohol during pregnancy?

It is not uncommon for a woman to drink alcohol before realising that she is pregnant. A very small number of studies do not raise concern that occasional binge drinking (5+ units) early in pregnancy poses a strong chance of problems in the baby. However, because so few pregnant women with this type of drinking pattern have been studied, more research is required to confirm this. 

Women who are worried about alcohol consumed during pregnancy can speak to their doctor or midwife. The chance of their baby being affected will largely depend upon the amount of alcohol consumed on each occasion and the number of drinking days (see the sections below for further details).

How can drinking in pregnancy harm my baby?

Drinking alcohol during pregnancy can cause a range of different problems in the baby, often referred to as Fetal Alcohol Spectrum Disorders (FASD). Some of the features of FASD may only become obvious when a child starts school, or later in life.  
Features of FASD include:

•    Learning and behavioural problems which can range from mild to severe.
•    Reduced growth in the womb and/or throughout life.
•    Altered facial appearance (narrow eyes, thin upper lip, poorly defined groove between top lip and nose) – this can be quite hard to detect unless by a specially trained doctor.
•    Abnormal brain development which can lead to the child having a very small skull and/or problems such as seizures.

The chance of a baby being born with FASD tends to be linked to the amount of alcohol they were exposed to in the womb (see below). Some children with FASD are affected by all of the problems listed above while others have only one or a few of these problems. Children who have all four of these types of problem are said to have Fetal Alcohol Syndrome (FAS). 

How much alcohol causes FASD?

Heavy drinking during pregnancy, usually measured as repeatedly drinking more than around five units of alcohol (2 large glasses of wine) per day, carries the greatest risk of a baby being affected with FASD. Both daily heavy drinking and repeated heavy binge drinking have now been linked to FASD. 

Other drinking patterns during pregnancy have not been well-researched. A small number of studies assessed children exposed in the womb to up to six drinks over a week (with some non-drinking days) at any stage of pregnancy. Some (but not all) identified possible adverse effects on learning and behaviour. Studies of small numbers of children exposed to low levels of alcohol at any stage of pregnancy (2 units up to twice a week) do not raise major concerns of adverse effects but these cannot be ruled out due to the low numbers of children assessed.

As there is currently no level of alcohol that has been proved to be safe for an unborn baby, the Department of Health recommends complete abstinence from alcohol during pregnancy. 

Can other factors influence the chance of FASD?

We can broadly say that across the population the chance of FASD is highest in children exposed in the womb repeatedly to large amounts of alcohol. However, other factors that naturally vary from person to person can influence each woman’s chance of having a baby with FASD. For some people this may mean that lower levels of alcohol have the potential to cause harm. These factors include:

•    The ability of the mother and fetus to process alcohol (this is largely determined by their genes).
•    The mother’s age, body weight, general health, nutritional status, and lifestyle.
•    Exposure to additional prescription or recreational drugs.

Is there any stage of pregnancy where it is considered safe(r) to drink alcohol?

No. Alcohol consumed at any stage of pregnancy can reach the baby.

Most of the baby’s body and organs are formed between weeks 3 and 8 of pregnancy and it is during this time that heavy drinking can potentially cause the facial differences linked to FASD. A number of structural birth defects (including heart, kidney and eye defects) have also been linked to alcohol exposure in early pregnancy.

A baby’s brain develops throughout the whole of pregnancy. Drinking alcohol at any time during pregnancy can therefore potentially damage the baby’s developing brain, leading to lifelong difficulties with thinking and learning, and behavioural problems. 

Will my baby need extra monitoring during pregnancy?

As part of their routine antenatal care most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects and to check the baby’s growth. It is important to understand that scans are not able to pick up all birth defects and will not detect more subtle changes to the brain that might be linked to some learning and behavioural problems.

In pregnancies where exposure to high levels of alcohol has occurred, other specific monitoring or more detailed tests may be offered.

Are there any risks to my baby if the father drank alcohol? 

We would not expect any increased risk to the baby if the father drank alcohol around the time of conception.

Who can I talk to if I have questions?

If you have any questions regarding the information in this leaflet, please discuss them with your health care provider. They can access more detailed medical and scientific information from Women who are concerned about alcohol exposure during pregnancy can speak to their GP.

How can I help to improve drug safety information for pregnant women in the future?

Our online reporting system (MyBump Portal) allows women who are currently pregnant to create a secure record of their pregnancy, collected through a series of questionnaires. You will be asked to enter information about your health, whether or not you take any medicines, your pregnancy outcome and your child's development. You can update your details at any time during pregnancy or afterwards. This information will help us better understand how medicines affect the health of pregnant women and their babies. Please visit the MyBump Portal to register.

General information
Sadly, miscarriage and birth defects can occur in any pregnancy.

Miscarriage occurs in about 1 in every 5 pregnancies, and 1 in every 40 babies are born with a birth defect. This is called the ‘background risk’ and happens whether medication is taken or not.

Most medicines cross the placenta and reach the baby. For many medications this is not a problem. However, some medicines can affect a baby’s growth and development.

If you take regular medication and are planning to conceive, you should discuss whether your medicine is safe to continue with your doctor/health care team before becoming pregnant. If you have an unplanned pregnancy while taking a medicine, you should tell your doctor as soon as possible.

If a new medicine is suggested for you during pregnancy, please make sure that the person prescribing it knows that you are pregnant. If you have any concerns about a medicine, you can check with your doctor, midwife or pharmacist.

Our Bumps information leaflets provide information about the effects of medicines in pregnancy so that you can decide, together with your healthcare provider, what is best for you and your baby.