Methodist Healthcare
January 08, 2019

While still in the womb, some babies have problems with how their organs and body parts form, how they work or how their bodies turn food into energy. These health problems are called birth defects.

There are more than 4,000 different kinds of birth defects, ranging from minor ones that need no treatment to serious ones that cause disabilities or require medical or surgical treatment. According to the March of Dimes, one out of every 33 babies born each year in the United States has a birth defect.

For people who want to become parents, it's important to know that some birth defects can be prevented. During a woman's pregnancy, taking folic acid and getting enough iodine in the diet can help prevent some types of birth defects. But it's also important to realize that most babies born with birth defects are born to two healthy parents with no obvious health problems or risk factors.


In most cases, doctors don't know what caused a baby's birth defect. When the cause is known, it might be environmental (such as a baby's exposure to chemicals or viruses while in the womb), a problem with the fetus' genes or a combination of these things.

Common birth defects

  • Cleft lip and/or palate 
  • Cerebral palsy 
  • Clubfoot 
  • Developmental dysplasia of the hip 
  • Congenital hypothyroidism
  • Fetal alcohol syndrome (FAS) 
  • Neural tube defects (NTD) (such as spina bifida and anencephaly)

Heart defects, gastrointestinal tract defects or genetic birth defects are also possibilities.

Infections can cause birth defects

Infections during pregnancy can cause a variety of birth defects.

Women who are pregnant should talk to their healthcare providers about ways to avoid these infections and what to do if they're exposed to them.

Diagnosing birth defects

Many birth defects are diagnosed even before a baby is born through prenatal tests. Prenatal tests also can help determine if a mother has an infection or other condition that is dangerous for the fetus. Knowing about a baby's health problems ahead of time can help parents and doctors plan for the future.

Defects that may be detected through prenatal screening include:

  • neural tube defects (spina bifida, anencephaly)
  • Down syndrome and other chromosome abnormalities
  • inherited metabolic disorders
  • congenital heart defects
  • gastrointestinal and kidney malformations
  • cleft lip or palate
  • certain birth defects of the limbs
  • congenital tumors

It's important to remember that screening identifies only the possibility that a baby has a defect. It's possible to give birth to a healthy baby after a screening test shows that a defect may be present. You aren't required to have any prenatal screening; talk to your doctor about any tests he or she thinks you should have.

Other birth defects that can't be detected before birth can be identified during routine newborn screenings. With parents' permission, babies are tested after birth to screen for certain birth defects that need to be treated soon after birth. Exactly what a baby is tested for varies from state to state, although all states screen for phenylketonuria (PKU), congenital hypothyroidism, sickle cell disease and about 30 other conditions identified using a technology called tandem mass spectroscopy. Parents should ask healthcare providers or the hospital nursery which tests their state performs routinely.

Other disorders that states may test newborns for include:

  • cystic fibrosis
  • congenital adrenal hyperplasia (an inherited disorder of the adrenal gland that can cause severe illness in newborns if not diagnosed and treated within the first few weeks of life)
  • hearing loss

Parents who have concerns about another specific birth defect might be able to have their baby tested for it. They should talk to their healthcare provider about it before the baby is born.

Preventing birth defects

Many birth defects can't be prevented, but a woman can do some things before and during pregnancy to help lower the chances of having a baby with a birth defect.

Before pregnancy, women should:

  • make sure their vaccinations are up-to-date
  • make sure they don't have any sexually transmitted diseases (STDs)
  • get the daily recommended dose of folic acid before trying to conceive
  • avoid unnecessary medicines and talk to their doctor about medicines they are taking

If there's a family history of birth defects or a woman is part of a high-risk group (due to age, ethnic background or medical history), she should consider meeting with a genetic counselor to determine her baby's risk.

During pregnancy, it's important to take prenatal vitamins and eat a healthy diet in addition to taking the following precautions:

  • don't smoke and avoid secondhand smoke
  • don't drink alcohol
  • avoid all illicit drugs
  • get exercise and plenty of rest
  • get early and regular prenatal care

By following these pregnancy precautions, women can help reduce their babies' risk of birth defects.