Folic acid/folate in pregnancy

Overview

Folic acid, sometimes called folate, is a vitamin that belongs to the vitamin B group. The body needs folic acid when cells are growing and dividing very quickly, this happens during pregnancy.

What are the benefits of folic acid in pregnancy?

Early in pregnancy, when the foetus is developing, folic acid plays an important role in the development of the neural tube. As the foetus grows, the neural tube develops into the brain and spinal cord. Sometimes an abnormality occurs when the neural tube does not close properly - this is known as a neural tube defect. This occurs in about one in 500 babies. Some examples of neural tube defects are spina bifida, where the spine or its covering stick out of the back, and anencephaly, in which the brain does not form properly. Babies born with these defects often die, or have problems with walking, and with bowel and bladder control.

Research shows that women who have a high level of folic acid before they become pregnant, are less likely to give birth to a baby with neural tube defects, and will prevent up to 70 per cent of these deformities.

Sources of folate

Foods:

Folate is found naturally in foods such as:

most vegetables, especially leafy green vegetables such as spinach
asparagus, oranges, corn
wholegrain breads
cereals
legumes such as peas, chickpeas, beans and lentils

It is best to eat fresh fruit and vegetables as cooking and prolonged storage destroys the folate.

Tablets:

Folic acid is also available in tablet form. If you are planning a pregnancy or are pregnant, the Ministry of Health advice for most women is to take one 800 microgram (mcg) folic acid tablet daily for at least four weeks before getting pregnant, and continue taking the tablet daily until the end of week 12 of your pregnancy. If you find you are pregnant during the first 12 weeks of pregnancy, you should take the tablet from that point until the end of week 12.

High-risk pregnancies

Some women are at increased risk of having a baby with a spinal cord problem, and will require higher doses of folic acid — 5 milligrams once a day. For example, if:

You have had a previous affected pregnancy.
You or your partner have a spinal cord defect.
You or your partner have family with a spinal cord defect.
You are taking medication that is known to affect folate metabolism such medication for epilepsy (eg, carbamazepine, sodium valproate), infertility treatment (eg, clomifene), and vitamin A analogues (eg etretinate).
You are on insulin treatment for diabetes.
You are obese- especially if your body mass index (BMI) is 30 or more.
You have coeliac disease, diabetes, sickle cell anemia or thalassaemia.