Birth Information Network

It is not clear how many birth defects are related to environmental exposures such as chemicals, drugs and radiation. Some endocrine-disrupting chemicals including polychlorinated biphenyls (PCBs), dioxins and pesticides, have been linked to nervous system defects and developmental problems such as reduced muscle tone and response. More data is needed to make these connections clearer.

Living near a hazardous waste site has been identified as a possible risk factor for birth defects such as neural tube defects, which affect the developing brain and spinal cord.

Exposure to disinfection by-products in drinking water such as trihalomethanes (THM) may increase the risk of some types of birth defects that affect the brain and spinal cord, the urinary tract and the heart.

Other environmental factors suspected to be associated with birth defects include arsenic, plastics, solvents and mercury.

The baby's development may be more susceptible to environmental exposures during the first trimester. This is the most sensitive time in pregnancy, when the organs and limbs are formed.

Birth defects are problems that develop while a fetus is growing during pregnancy. These problems can cause physical and mental disabilities, and may result in death.  There are thousands of different birth defects. Most occur in the first three months of pregnancy.

Most birth defects are thought to be caused by a complex mix of factors, including a person’s genes, behaviors and things in the environment. For some birth defects, the cause is known, but for most, the cause or causes are still unknown.

Some women are at higher risk of having a child with a birth defect, for example:

• The mother’s age can play a part. Women over the age of 35 and below the age of 17 are more likely to have a child with Down syndrome than other women. Teenage mothers are more likely to have a baby born with gastroschisis, which is a defect in the abdominal wall.
• Women who smoke or use alcohol while pregnant have a higher risk of having a baby with certain birth defects. Some street drugs and some prescription drugs can also cause birth defects.
• Women with certain medical conditions such as diabetes or obesity are at higher risk.
• Certain infections during pregnancy can affect the development of a growing fetus.

The father’s age can increase the risk of having a child with a birth defect. Men over about 37 ½ years of age are at higher risk of having a child with certain genetic syndromes. These are syndromes caused by single small genetic changes that can happen in sperm of older men.

Other birth defects are also caused by genetic factors. These birth defects may run in families, but they may also occur when no one else in the family has this problem.

• To provide accurate counts of children with special health needs to make sure that parents and infants can get the services they need.
• To understand why some children are born with serious health concerns.
• To prevent or reduce the impact of birth defects and other conditions.
• To improve overall health services.

Currently, Vermont collects information about 47 structural and chromosomal birth defects, 28 metabolic and endocrine conditions, congenital hearing loss, and very low birth weight (infant born with a birth weight less than 1500 grams). 

• List of Birth Defects