Health Topics

Genetics birth defects

Genetic Counseling
National Library of Medicine

Genetic counseling provides information and support to people who have, or may be at risk for, genetic disorders. A genetic counselor meets with you to discuss genetic risks. The counseling may be for yourself or a family member. Or you may get it when you are planning or expecting a baby. You may follow up with genetic testing.

There are many reasons to seek genetic counseling. You may consider it if you :

  • Have a personal or family history of a genetic condition or birth defect
  • Are pregnant or planning to be pregnant after age 35
  • Already have a child with a genetic disorder or birth defect
  • Have had two or more pregnancy losses or a baby who died
  • Have had ultrasound or screening tests that suggest a possible problem

Genetics Home Reference


Genetic Counseling
Pregnancy and Reproduction
Genetics/Birth Defects
Genetic counseling provides information and support to people who have, or may be at risk for, genetic disorders. A genetic counselor meets with you to discuss ...
Newborn Screening
National Library of Medicine
Screening, Newborn

Your newborn infant has screening tests before leaving the hospital. There may be different tests depending on the state where you live. They include:

  • Tests on a few drops of blood from pricking the baby's heel. The tests look for inherited disorders. All states test for at least 30 of these conditions.
  • A hearing test that measures the baby's response to sound
  • A skin test that measures the level of oxygen in the blood. This can tell if the baby has a congenital heart defect.

These tests look for serious medical conditions. If not treated, some of these conditions can cause lifelong health problems. Others can cause early death. With early diagnosis, treatment can begin right away, before serious problems can occur or become permanent.

If a screening shows that your baby might have a condition, the health care provider or the state health department will call you. It is important to follow up quickly. Further testing can verify whether your baby has the condition. If so, treatment should start right away.

NIH: National Institute of Child Health and Human Development


Neonatal Screening
Children and Teenagers
Genetics/Birth Defects
Your newborn infant has screening tests before leaving the hospital. There may be different tests depending on the state where you live. They include: Tests ...
Birth Defects
National Library of Medicine
Abnormalities
What are birth defects?

A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of pregnancy. One out of every 33 babies in the United States is born with a birth defect.

A birth defect may affect how the body looks, works, or both. Some birth defects like cleft lip or neural tube defects are structural problems that can be easy to see. Others, like heart disease, are found using special tests. Birth defects can range from mild to severe. How a birth defect affects a child's life depends mostly on which organ or body part is involved and how severe the defect is.

What causes birth defects?

For some birth defects, researchers know the cause. But for many birth defects, the exact cause is unknown. Researchers think that most birth defects are caused by a complex mix of factors, which can include:

  • Genetics. One or more genes might have a change or mutation that prevents them from working properly. For example, this happens in Fragile X syndrome. With some defects, a gene or part of the gene might be missing.
  • Chromosomal problems. In some cases, a chromosome or part of a chromosome might be missing. This is what happens in Turner syndrome. In other cases, such as with Down syndrome, the child has an extra chromosome.
  • Exposures to medicines, chemicals, or other toxic substances. For example, alcohol misuse can cause fetal alcohol spectrum disorders.
  • Infections during pregnancy. For example, infection with Zika virus during pregnancy can cause a serious defect in the brain.
  • Lack of certain nutrients. Not getting enough folic acid before and during pregnancy is a key factor in causing neural tube defects.
Who is at risk of having a baby with birth defects?

Certain factors may might increase the chances of having a baby with a birth defect, such as:

  • Smoking, drinking alcohol, or taking certain "street" drugs during pregnancy
  • Having certain medical conditions, such as obesity or uncontrolled diabetes, before and during pregnancy
  • Taking certain medicines
  • Having someone in your family with a birth defect. To learn more about your risk of having a baby with a birth defect, you can talk with a genetic counselor,
  • Being an older mother, typically over the age of 34 years
How are birth defects diagnosed?

Health care providers can diagnose some birth defects during pregnancy, using prenatal testing. That's why it important to get regular prenatal care.

Other birth defects may not be found until after the baby is born. Providers may find them through newborn screening. Some defects, such as club foot, are obvious right away. Other times, the health care provider may not discover a defect until later in life, when the child has symptoms.

What are the treatments for birth defects?

Children with birth defects often need special care and treatments. Because the symptoms and problems caused by birth defects vary, the treatments also vary. Possible treatments may include surgery, medicines, assistive devices, physical therapy, and speech therapy.

Often, children with birth defects need a variety of services and may need to see several specialists. The primary health care provider can coordinate the special care that the child needs.

Can birth defects be prevented?

Not all birth defects can be prevented. But there are things you can do before and during pregnancy to increase your chance of having a healthy baby:

  • Start prenatal care as soon as you think you might be pregnant, and see your health care provider regularly during pregnancy
  • Get 400 micrograms (mcg) of folic acid every day. If possible, you should start taking it at least one month before you get pregnant.
  • Don't drink alcohol, smoke, or use "street" drugs
  • Talk to your health care provider about any medicines you are taking or thinking about taking. This includes prescription and over-the-counter medicines, as well as dietary or herbal supplements.
  • Learn how to prevent infections during pregnancy
  • If you have any medical conditions, try to get them under control before you get pregnant

Centers for Disease Control and Prevention


Congenital Abnormalities
Genetics/Birth Defects
What are birth defects? A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the ...
Brain Malformations
National Library of Medicine
Cephalic Disorders

Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it to develop abnormally. Sometimes it's a genetic problem. In other cases, exposure to certain medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, abnormally small or large, or not fully developed.

Treatment depends upon the problem. In many cases, treatment only helps with symptoms. It may include antiseizure medicines, shunts to drain fluid from the brain, and physical therapy.

There are head malformations that do not involve the brain. Craniofacial disorders are the result of abnormal growth of soft tissue and bones in the face and head. It's common for new babies to have slightly uneven heads, but parents should watch the shape of their baby's head for possible problems.

NIH: National Institute of Neurological Disorders and Stroke


Nervous System Malformations
Brain and Nerves
Genetics/Birth Defects
Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it to develop abnormally. Sometimes it's ...
Prenatal Testing
National Library of Medicine
Amniocentesis
Chorionic Villi Sampling
Fetal Ultrasound

Prenatal testing provides information about your baby's health before he or she is born. Some routine tests during pregnancy also check on your health. At your first prenatal visit, your health care provider will test for a number of things, including problems with your blood, signs of infections, and whether you are immune to rubella (German measles) and chickenpox.

Throughout your pregnancy, your health care provider may suggest a number of other tests, too. Some tests are suggested for all women, such as screenings for gestational diabetes, Down syndrome, and HIV. Other tests might be offered based on your:

  • Age
  • Personal or family medical history
  • Ethnic background
  • Results of routine tests

There are two types of tests:

  • Screening tests are tests that are done to see if you or your baby might have certain problems. They evaluate risk, but do not diagnose problems. If your screening test result is abnormal, it does not mean that there is a problem. It means that more information is needed. Your health care provider can explain what the test results mean and possible next steps. You may need diagnostic testing.
  • Diagnostic tests show whether or not you or your baby have a certain problem.

It is your choice whether or not to get the prenatal tests. You and your health care provider can discuss the risks and benefits of the tests, and what kind of information the tests can give you. Then you can decide which ones are right for you.

Dept. of Health and Human Services Office on Women's Health


Prenatal Diagnosis
Pregnancy and Reproduction
Genetics/Birth Defects
Diagnostic Tests
Female Reproductive System
Prenatal testing provides information about your baby's health before he or she is born. Some routine tests during pregnancy also check on your health. At your ...
Craniofacial Abnormalities
National Library of Medicine
Craniosynostosis
Positional Plagiocephaly
Treacher-Collins Syndrome

Craniofacial is a medical term that relates to the bones of the skull and face. Craniofacial abnormalities are birth defects of the face or head. Some, like cleft lip and palate, are among the most common of all birth defects. Others are very rare. Most of them affect how a person's face or head looks. These conditions may also affect other parts of the body.

Treatment depends on the type of problem. Plastic and reconstructive surgery may help the person's appearance.


Craniofacial Abnormalities
Bones, Joints and Muscles
Brain and Nerves
Genetics/Birth Defects
Craniofacial is a medical term that relates to the bones of the skull and face. Craniofacial abnormalities are birth defects of the face or head. Some, like cleft ...
Metabolic Disorders
National Library of Medicine
Mucolipidoses

Metabolism is the process your body uses to get or make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system break the food parts down into sugars and acids, your body's fuel. Your body can use this fuel right away, or it can store the energy in your body tissues, such as your liver, muscles, and body fat.

A metabolic disorder occurs when abnormal chemical reactions in your body disrupt this process. When this happens, you might have too much of some substances or too little of other ones that you need to stay healthy. There are different groups of disorders. Some affect the breakdown of amino acids, carbohydrates, or lipids. Another group, mitochondrial diseases, affects the parts of the cells that produce the energy.

You can develop a metabolic disorder when some organs, such as your liver or pancreas, become diseased or do not function normally. Diabetes is an example.


Metabolic Diseases
Genetics/Birth Defects
Metabolic Problems
Metabolism is the process your body uses to get or make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive ...
Genetic Disorders
National Library of Medicine
Progeria

Genes are the building blocks of heredity. They are passed from parent to child. They hold DNA, the instructions for making proteins. Proteins do most of the work in cells. They move molecules from one place to another, build structures, break down toxins, and do many other maintenance jobs.

Sometimes there is a mutation, a change in a gene or genes. The mutation changes the gene's instructions for making a protein, so the protein does not work properly or is missing entirely. This can cause a medical condition called a genetic disorder.

You can inherit a gene mutation from one or both parents. A mutation can also happen during your lifetime.

There are three types of genetic disorders:

  • Single-gene disorders, where a mutation affects one gene. Sickle cell anemia is an example.
  • Chromosomal disorders, where chromosomes (or parts of chromosomes) are missing or changed. Chromosomes are the structures that hold our genes. Down syndrome is a chromosomal disorder.
  • Complex disorders, where there are mutations in two or more genes. Often your lifestyle and environment also play a role. Colon cancer is an example.

Genetic tests on blood and other tissue can identify genetic disorders.

NIH: National Library of Medicine


Genetic Diseases, Inborn
Genetics/Birth Defects
Genes are the building blocks of heredity. They are passed from parent to child. They hold DNA, the instructions for making proteins. Proteins do most of the ...
Color Blindness
National Library of Medicine

Most of us see our world in color. We enjoy looking at a lush green lawn or a red rose in full bloom. If you have a color vision defect, you may see these colors differently than most people.

There are three main kinds of color vision defects. Red-green color vision defects are the most common. This type occurs in men more than in women. The other major types are blue-yellow color vision defects and a complete absence of color vision.

Most of the time, color blindness is genetic. There is no treatment, but most people adjust and the condition doesn't limit their activities.


Color Vision Defects
Eyes and Vision
Genetics/Birth Defects
Most of us see our world in color. We enjoy looking at a lush green lawn or a red rose in full bloom. If you have a color vision defect, you may see these ...
Genes and Gene Therapy
National Library of Medicine
Human Genome Project

Genes are the building blocks of inheritance. Passed from parent to child, they contain instructions for making proteins. If genes don't produce the right proteins or don't produce them correctly, a child can have a genetic disorder.

Gene therapy is an experimental technique that uses genes to treat or prevent disease. The most common form of gene therapy involves inserting a normal gene to replace an abnormal gene. Other approaches include:

  • Swapping an abnormal gene for a normal one
  • Repairing an abnormal gene
  • Altering the degree to which a gene is turned on or off

Although there is much hope for gene therapy, it is still experimental.

Genetics Home Reference


Genetic Therapy
Genes
Genetics/Birth Defects
Genes are the building blocks of inheritance. Passed from parent to child, they contain instructions for making proteins. If genes don't produce the right ...