Preventing Birth Defects

Folic acid has been proven to help reduce the risk of neural tube defects (NTDs) by as much as 70% if taken before pregnancy and during the first trimester. But many women don’t know the benefits of folic acid, or when to take it and where to find it.

What are birth defects? | How are birth defects treated?
What are neural tube defects (NTDs)?
Who is at risk of having a baby with NTDs? 
Can NTDs be detected before birth?  | Supporting Prevention

What are birth defects?

Birth defects are structural or functional abnormalities present at birth that cause physical or mental disability. Researchers have identified thousands of different birth defects. Some may be fatal.

About two to three percent of babies born have some type of major birth defect. The risk of some problems, due to abnormal separation of genetic material (chromosomes), increases with the mother’s age. Currently, birth defects are the leading cause of death for infants during the first year of life.

Birth defects have a variety of causes, including the following:

  • genetic problems caused when one or more genes don’t work properly or part of a gene is missing,
  • problems with chromosomes, such as having an extra chromosome or missing part of a chromosome, and
  • environmental factors that a woman is exposed to during pregnancy, such as rubella or German measles while pregnant, or using drugs or alcohol during pregnancy.

There are two main types of birth defects: structural and functional. Structural birth defects are related to a problem with body parts. Functional birth defects are related to a problem with how a body part or body system works.

Some structural problems include cleft lip or cleft palate, heart defects such as missing or misshaped valves, and abnormal limbs, such as a club foot. They also include neural tube defects such as spina bifida – problems that are related to the growth and development of the brain and spinal cord.

Functional problems often lead to developmental disabilities and can include things such as:

  • nervous system or brain problems – such as learning disabilities, intellectual and developmental disabilities, behavioural disorders, speech or language difficulties, convulsions and movement trouble – including autism, Down syndrome, Prader-Willi syndrome, and Fragile X syndrome;
  • sensory problems – such as blindness, cataracts and other visual problems, and varying degrees of hearing loss (including deafness);
  • metabolic disorders – which involve a body process or chemical pathway or reaction, such as conditions that limit the body's ability to get rid of waste materials or harmful chemicals – including phenylketonuria (PKU) and hypothyroidism; and
  • degenerative disorders – conditions that might not be obvious at birth but cause one or more aspects of health to steadily get worse – including X-linked adrenoleukodystrophy (X-ALD), Rett syndrome, muscular dystrophy and lysosomal disorders.

In some cases, birth defects are caused by a combination of factors. Some recognized patterns of birth defects affect many parts or processes in the body, leading to both structural and functional problems.

National Institute of Child Health & Human Development,, February 28, 2011.
The Society of Obstetricians and Gynaecologists of Canada (SOGC),, February 28, 2011.

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How are birth defects treated?

Treatments for birth defects vary by disorder. Some NTDs can be detected before birth (see below). Some can also be prevented. For example, ensuring sufficient intake of folic acid 3 months before pregnancy and throughout the first trimester can significantly reduce the risks associated with certain neural tube defects, including spina bifida.

For more information, review this website, visit and other links on this site, and be sure to talk with your healthcare provider.

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What are neural tube defects (NTDs)?

Neural tube defects are birth defects that affect the brain (anencephaly) and/or spinal cord (spina bifida). NTDs occur when the tissues that form the brain and spinal cord fail to develop properly. These defects occur in the first four weeks after conception – usually before a woman even knows she is pregnant.

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Who is at risk of having a baby with NTDs?

Any woman who could become pregnant is at risk of having a baby with a neural tube defect. About 1 in every 1,300 pregnancies in Canada is affected by NTDs.

High-risk women include those women who:

  • are not getting enough folic acid,
  • have had a previous pregnancy affected by NTDs,
  • have (or have a partner who has) a family history of NTDs,
  • have insulin-dependent diabetes,
  • use certain anti-seizure medications,
  • have clinically diagnosed obesity, and/or
  • are of Celtic, Northern Chinese, Cree or Sikh heritage.

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Can NTDs be detected before birth?

Some NTDs can be detected before birth. Talk to your healthcare provider if you wish to know more about the prenatal blood test (maternal serum screening, triple test) or ultrasound test that can give you more information about whether your developing baby has a neural tube defect.

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Supporting Prevention

The mission of the Spina Bifida & Hydrocephalus Association of Ontario is “to build awareness and drive education, research, support, care and advocacy to help find a cure while always continuing to improve the quality of life of all individuals with spina bifida and/or hydrocephalus.”

Our Folic Acid: It’s never too earlycampaign is designed to increase the number of women taking a daily multivitamin containing folic acid and ultimately to prevent the occurence of NTDs.

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