A birth defect (congenital anomaly) is a health problem or abnormal physical change that is present when a baby is born.
Birth defects can be very mild, where the baby looks and acts like any other baby. Or birth defects can be more severe. Some birth defects cause a single problem. Others cause problems in more than 1 body system or organ. Birth defects may cause lifelong disability and illness. Some severe birth defects can be life-threatening. A baby may live for only a few weeks or months. Or a child may die at a young age, such as when they are a teen.
Some birth defects can’t be cured. These include defects that cause learning or thinking problems. But many physical birth defects can be treated with surgery. Repair is possible for many birth defects, including cleft lip or cleft palate, and certain heart defects.
When a baby is born with a birth defect, the first question often asked by the parents is "How did this happen?" Sometimes this question can’t be answered. This can be very upsetting for parents. It’s normal to want to know why your baby has a health problem.
Birth defects can happen for many reasons. They can happen because of the mother’s exposure to certain environmental factors, infections, or illegal drugs. They can also occur if there is a vitamin deficiency during pregnancy. Or they can happen because of certain genes or changes in genes (mutations). It could also be a combination of these things. But often the cause isn’t known.
The different causes of birth defects include:
Inheritance and gene defects. Inheritance means a trait passed on to you from a parent. Examples of normal inherited traits are eye color and blood type. Genes are what give you your traits. Sometimes a child can inherit not only those genes for normal traits such as eye color, but also disease-causing genes that cause a birth defect.
Chromosome problems. Chromosomes are stick-like structures in the center (nucleus) of each cell. Chromosomes contain your genes. Changes in chromosomes can cause health problems.
Multifactorial inheritance. This means that many things are involved in causing a birth defect. These things are often both genetic and environmental.
Teratogens. A teratogen is a substance that can cause a birth defect. It is often something in the environment that the mother may be exposed to during pregnancy. It could be a prescribed medicine, an illegal drug, alcohol use, a toxic chemical, or a disease that the mother has. Any of these could increase the chance for the baby to be born with a birth defect.
Birth defects are found in babies all over the world, in families from all countries and backgrounds. Any time a person becomes pregnant, there is a chance the baby will have a birth defect. Most babies are born healthy. But almost 1 in every 33 babies born in the U.S. has a major birth defect. The risk for birth defects varies by type of defect, family health history, age of parents, and other factors. Your healthcare provider can tell you more about your child’s risk for birth defects.
Symptoms vary widely. They depend on the type of birth defect. Symptoms can be a bit different for each child. They can include things such as:
Abnormal shape of the head, eyes, ears, mouth, or face
Abnormal shape of the hands, feet, or limbs
Spinal cord that isn't fully enclosed (spina bifida)
The symptoms of birth defects can seem like other health conditions. Have your child see their healthcare provider for a diagnosis.
Many birth defects can be diagnosed before birth with tests. Chromosome problems such as Down syndrome can be diagnosed before birth by looking at cells in the amniotic fluid or from the placenta. Or they can be found by looking at the baby’s DNA in the mother’s blood (noninvasive prenatal screening). These tests are very accurate.
Fetal ultrasound during pregnancy can also show the possibility of certain birth defects. But ultrasound is not 100% accurate. Some babies with birth defects may look the same on ultrasound as those without problems.
Tests that can be done while a baby is in the uterus include the following:
This blood test measures the levels of a protein called AFP (alpha-fetoprotein). This protein is released by the baby’s liver and is found in the mother's blood. AFP is sometimes called maternal serum AFP (MSAFP). AFP screening may be 1 part of a 2-, 3-, or 4-part screening. It's often called a multiple marker screen. The other parts are:
Human chorionic gonadotropin (hCG). This is a hormone released by some cells in the placenta. High hCG levels may mean that the baby has Down syndrome. This condition is a chromosome problem. It causes learning problems and some physical changes.
Estriol. This is a hormone made by the placenta, and by the baby’s liver and adrenal glands. Low levels may mean the baby has Down syndrome.
Inhibin. This is a hormone made by the placenta. Abnormal levels may mean an increased risk for Down syndrome.
This is an ultrasound test often done late in the first trimester. Thickening of the area at the back of the baby’s neck may mean an increased risk for Down syndrome or other chromosome problems.
This test takes a small sample of the amniotic fluid that surrounds the baby. The sample is used to diagnose chromosome problems and open neural tube defects such as spina bifida. Testing can be done for other genetic defects and disorders. This depends on family history and lab testing available at the time of the test. The American College of Obstetricians and Gynecologists advises amniocentesis around 15 to 20 weeks of pregnancy for women who are at higher risk for chromosome problems. These include women who are older than age 35 at delivery. It also includes women who have had an abnormal blood test that means they are at higher risk for a chromosome problem or neural tube defect such as spina bifida. In some cases, amniocentesis may be done as early as 14 weeks.
This test takes a sample of some tissue from the placenta. This tissue has the same genetic material as the baby. It can be tested for chromosome problems and some other genetic problems. This depends on family history and lab testing available at the time of the test. Unlike amniocentesis, CVS does not give information on neural tube defects such as spina bifida. Women who have the CVS test also need a follow-up blood test between 16 and 18 weeks of pregnancy. This blood test is to screen for neural tube defects.
This test uses sound waves to create an image of the internal organs. Some physical birth defects can be found with ultrasound.
This test looks at the mother's blood. The lab looks for genetic material called DNA that comes from the placenta. This DNA is the same as the baby’s DNA. The lab looks for chromosome problems such as trisomy 13, trisomy 18, and trisomy 21.
Sometimes birth defects are not diagnosed until after birth. A baby may be diagnosed with a physical exam by a healthcare provider. The healthcare provider may also take a blood sample. The sample is looked at in a lab to find chromosome problems. This is important so the parents know the risk for that birth defect in future pregnancies.
There is no cure for birth defects. But children can often be treated to help reduce problems. Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is. Children may benefit from surgery, medicines, physical or occupational therapy, education intervention, and other types of help. Talk with your child’s healthcare providers about the risks, benefits, and possible side effects of all treatments.
Possible complications vary widely by type of birth defect. They may include 1 or more of the following:
Middle ear infections
High blood pressure
Chronic lung disease
Attention-deficit/hyperactivity disorder (ADHD)
Obsessive compulsive disorder (OCD)
Researchers are trying to find ways to prevent many birth defects. Not all birth defects can be prevented. There are only a few ways currently known to help prevent certain defects. Taking steps to be healthy before and during pregnancy is important. Getting vaccinated against certain infections such as rubella can prevent birth defects caused by that infection. Not drinking during pregnancy can prevent birth defects caused by alcohol. Taking a prenatal vitamin that includes folic acid can help prevent neural tube defects such as spina bifida.
If your baby is born with a birth defect, you can do certain things to take care of yourself and your baby:
Keep all appointments with your baby’s healthcare provider.
Talk with your healthcare provider about other providers who will be included in your child’s care. Your child may receive care from a multidisciplinary team. This team may include counselors, social workers, clergy, genetic counselors, dietitians, physical therapists, and speech therapists. Your child’s care team will depend on your baby’s condition.
Call your provider if you are concerned about your baby’s symptoms.
Think about having genetic testing and counseling to understand your risk.
Tell others of your baby’s condition. Work with your child’s healthcare provider to create a treatment plan.
Ask for support from local community services. This may include your faith community and organizations that specialize in birth defects, such as the March of Dimes.
A birth defect is a health problem or abnormal physical change that is present when a baby is born. Birth defects range from very mild to life-threatening and limiting.
Birth defects can happen for many reasons. But often the cause isn’t known.
Many birth defects can be diagnosed before birth with tests. Your healthcare provider will talk with you about testing.
The risk for birth defects varies by type of defect, family health history, age of parents, and other factors. Your provider can tell you more about your risk of having a child with a birth defect.
There is no cure for birth defects. But children can often be treated to help reduce problems.
Researchers are trying to find ways to prevent many birth defects. Not all birth defects can be prevented. Taking steps to be healthy before and during pregnancy is important.
Tips to help you get the most from a visit to your child’s healthcare provider:
Know the reason for the visit and what you want to happen.
Before your visit, write down questions you want answered.
At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
Ask if your child’s condition can be treated in other ways.
Know why a test or procedure is advised and what the results could mean.
Know what to expect if your child does not take the medicine or have the test or procedure.
If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.