It is not clear how many birth defects are related to environmental exposures, such as chemicals, drugs, and ionizing 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. We need more data, though, 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 are defects in the development of the brain and spinal cord, and heart and blood vessel defects. Exposure to disinfection by-products
in drinking water such as trihalomethanes, or THM, may increase the risk of some types of birth defects which affect the brain and spinal cord, the urinary tract, and the heart.
Women over the age of 35 years have an increasing chance of having a child with Down syndrome than women who are younger. Teenage mothers are more likely to have a baby born with gastrochisis—a defect in the abdominal wall.
Some birth defects are caused by genetic problems. Sometimes, these birth defects run in families, but other times they will occur even when there is no one else in the family who has this problem. Communities or populations from a shared heritage may see higher incidences of a specific genetic problem. The root causes of genetic problems are difficult to pinpoint, but even these may have relationships to past environments or a combination of other factors. Preliminary research has shown there may be a potentially higher than normal frequency of certain rare genetic disorders among the Acadian people
. To learn more about your risk of having a baby with a genetic abnormality, you can talk with a clinical geneticist or genetic counselor