Folic acid

Print
Date: May 2025, Version 3

Quick read

You should take a folic acid supplement whilst trying to conceive and for the first 12 weeks of pregnancy to reduce the chance of certain birth defects in your baby.

What is it?

Folic acid is a vitamin supplement that is converted to folate in the body. It is recommended that all women who are pregnant or planning a pregnancy take folic acid until at least the 12th week of pregnancy.

Why do I need to take folic acid during pregnancy?

Folate is essential for a developing baby. Low folate levels have been strongly linked to spina bifida and other birth defects affecting the brain, skull, and spinal cord. Folic acid supplements can reduce the chance of these problems in your baby.

How much folic acid is recommended during pregnancy?

Most women are advised to take a supplement containing a daily dose of around 400 micrograms (mcg) of folic acid. Most pregnancy supplements that you can buy in the UK contain this dose of folic acid.

If you are taking certain medicines (for example, to treat epilepsy), have a health condition like diabetes, or have a close family member with a neural tube defect, your doctor will prescribe you a higher daily dose of 5 milligrams (mg) folic acid. 

Will my baby need extra monitoring if I haven’t taken folic acid?

Most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects as part of their routine antenatal care. Not taking folic acid during early pregnancy would not normally require extra monitoring of your baby. However, if you are thought to be at risk of folate deficiency or have a family history of spina bifida or related birth defects, your doctor may advise a more detailed ultrasound scan or further tests.

Methylfolate - what is it, and can I take it instead of folic acid?

Methylfolate is related to folic acid and is available in some supplements. Although it is thought to work in a similar way to folic acid, there are no formal studies showing that methylfolate reduces the chance of birth defects. UK guidelines continue to recommend folic acid during pregnancy and while trying to conceive.

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 www.uktis.org.

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.