What Are Birth Defects? Types, Causes, Treatment & Prevention

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Birth defects, also called congenital disorders, may cause physical, developmental, or intellectual disabilities in infants. These conditions are present at birth and often require medical intervention to ensure the baby has a good quality of life.

Statistics prove that in the US, a baby with congenital defects is born every four and a half minutes (1). Congenital disabilities lead to structural and metabolic differences. They may cause minor health issues that do not need any treatment to severe conditions that may require surgical intervention.

This post discusses the different types, causes, diagnoses, treatment, and prevention of congenital disabilities in babies.

Types Of Birth Defects

Birth defects can be classified into (2):

1. Structural birth defects

If a baby is born with a missing or malformed part of the body, it is known as a structural birth defect. These congenital disorders may include:

  • Heart defects (most common)
  • Cleft palate
  • Cleft lip
  • Neural tube defects, such as spina bifida
  • Anencephaly
  • Limb anomalies, such as clubfoot
  • Congenital dislocated hip

2. Functional or developmental birth defects

Functional or developmental birth defects are changes in the body’s functions or any part or system of the body. These may include:

  • Metabolic birth defects, also called inborn errors of metabolism, which are caused by issues in the body’s chemicals. Inherited single-gene mutations cause most of these congenital metabolic disorders.
  • Degenerative disorders, such as muscular dystrophy and adrenoleukodystrophy, which cause progressive deterioration of parts or systems of the body.
  • Nervous system or brain problems, such as intellectual or developmental disabilities, language and speech problems, and behavioral problems.

Metabolic birth defects may interfere with the body’s chemical reactions, such as breaking down of food in the digestive tract for energy. When there is a lack of chemicals to complete bodily functions, babies may have complications due to the accumulation or absence of substances.

The following are common metabolic birth defects.

  • Tay-Sachs disease
  • Phenylketonuria (PKU)
  • Lysosomal storage disorders
  • Glycogen storage disease
  • Maple syrup urine disease
  • Alkaptonuria
  • Mitochondrial respiratory chain disorders

Structural and metabolic birth defects could impact normal body functions in babies. Early diagnosis and management may give favorable outcomes.

Causes Of Birth Defects

The exact cause of birth defects may not be identified in many cases. It can be due to environmental or genetic factors or both. Maternal exposure to environmental factors, such as toxins, viral infections, and other infections during pregnancy, may result in birth defects.

These may include (3):

  • Toxoplasmosis
  • Chickenpox (varicella)
  • Rubella
  • Alcohol use (this could lead to fetal alcohol syndrome)
  • Certain medications
  • Toxic chemicals

Genetic factors, such as damage to chromosomes or too few or too many chromosomes, are common genetic causes of birth defects in babies. These may include (3):

  • Down syndrome
  • Achondroplasia (dwarfism)
  • Marfan syndrome
  • Hemophilia
  • Color blindness

Mothers who are not vaccinated are more likely to develop viral infections during pregnancy. Seeking a prescription before taking over-the-counter medications may help avoid medicines that are not safe in pregnancy. It is recommended to seek a preconception consultation to get necessary vaccinations and required supplementation when planning for pregnancy.

Diagnosis Of Birth Defects 

Prenatal tests may help determine many of the birth defects before the baby is born. These may also help identify any maternal conditions or infections that can be dangerous for the fetus. Parents can plan the future based on the prenatal tests (4).

Some structural birth defects are often noticeable after birth. Structural abnormalities, such as heart defects, are diagnosed based on symptoms and echocardiography. The symptoms, blood tests, and other laboratory analyses may help identify inborn errors of metabolism in babies.

Early newborn screening may include tests to determine common metabolic and genetic abnormalities, such as phenylketonuria (PKU) and other abnormalities. Early detection and treatment may help avoid complications in many babies.

Treatment For Birth Defects

Treatment options may vary according to the type and severity of the birth defect. Some babies may not require any interventions, and they grow and thrive regardless of the congenital disability. In contrast, some conditions, such as heart defects or a cleft palate or lip, may require special assistive devices or surgeries to ensure normal development (5).

Inborn errors of metabolism may require early treatments or precautions since the accumulation or lack of substance could cause organ damages. Gene therapies and specific enzyme replacement therapies may be beneficial for some babies. Diet modifications are often useful in phenylketonuria and some other metabolic disorders.

The pediatrician may suggest a long-term treatment plan based on the severity of the birth defect and health status of the baby.

Prevention Of Birth Defects

Many birth defects are caused by genetic factors that cannot be prevented. Good preconception and prenatal care may help lower the risk of birth defects due to environmental factors. Pregnant women should take the following precautionary measures to reduce the risk of birth defects (6).

  • Get early and regular prenatal care
  • Get the necessary vaccinations
  • Test for sexually transmitted diseases (STDs) and other infections; get them treated before conception or immediately after diagnosis
  • Take daily recommended dose of folic acid and other supplements
  • Eat healthily and do regular physical activity as recommended
  • Avoid taking OTC medications; always seek prescription mentioning that you are pregnant
  • Consider genetic counseling if there is a positive family history of congenital defects
  • Avoid cigarette smoking and secondhand exposure to smoke
  • Avoid alcohol and all illicit drugs
  • Keep medical conditions, such as diabetes or hypertension under control
  • Get adequate rest and avoid stress

Early prenatal care should not be avoided since most defects often occur during the first trimester. Nevertheless, it is essential to take the necessary precautions throughout pregnancy since birth defects may occur at any stage of pregnancy.

Babies may require consistent special care to survive birth defects. You may ask the pediatrician for programs that provide home services and financial support. You may also plan the appropriate care for your baby with their doctors to improve their quality of life. In several cases, adequate intervention lets the baby with the birth defect thrive and live a life with no limitations.

Key Pointers

  • Birth defects can be categorized into structural and functional or developmental.
  • Prenatal infections and certain genetic disorders such as Down syndrome and Hemophilia can increase the risk of birth defects in babies.
  • Adequate prenatal care, including good nutrition, physical activity, and maternal vaccinations, may help prevent certain congenital disorders in infants.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
1. Birth Defects; Centers for Disease Control and Prevention
2. What are the types of birth defects?; Eunice Kennedy Shriver National Institute of Child Health and Human Development
3. What are birth defects?; Centers for Disease Control and Prevention
4. Birth Defects and Congenital Anomalies | Testing and Diagnosis; Boston Children’s Hospital
5. Birth Defects; MedlinePlus; The United States National Library of Medicine
6. Commit to Healthy Choices to Help Prevent Birth Defects; Centers for Disease Control and Prevention
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Dr. Richard Mario Lurshay

Dr. Richard Mario Lurshay is a young and talented pediatrician, well known for his work with children. After completing his post-graduation in Pediatrics, he completed his training in Pediatric Nutrition from Boston University School of Medicine (USA). He is an esteemed Life Member of National Academy of Medical Sciences (NAMS), National Neonatology Forum (NNF) and Indian Academy of Paediatrics (IAP).... more

Dr Bisny T. Joseph

Dr. Bisny T. Joseph is a Georgian Board-certified physician. She has completed her professional graduate degree as a medical doctor from Tbilisi State Medical University, Georgia. She has 3+ years of experience in various sectors of medical affairs as a physician, medical reviewer, medical writer, health coach, and Q&A expert. Her interest in digital medical education and patient education made... more