Authored by Revere Health

Birth Defects: A Risk of Pregnancy

September 27, 2016 | OB/GYN

OBGYN - What to Expect AFTER Expecting

Pregnancy is a time of joy, but it can also be a time of worry. While most babies born in the United States are healthy, many are at risk for birth defects.

Birth defects affect about 3 percent of babies born in the U.S. every year, according to the Centers for Disease Control and Prevention (CDC), which is about one in every 33 babies. This means about 120,000 babies are born each year with physical problems that affect how their organs or body parts form and function. Sadly, birth defects are responsible for about 20 percent of all infant deaths, but proper care from an OB/GYN professional can reduce these risks.


About Birth Defects

There are more than 4,000 different types of birth defects. Some defects can be so slight that their effects are not apparent for many years and require little medical care. Other defects are significant, apparent at birth, and require immediate attention.

Medical professionals classify birth defects as structural or metabolic. A baby born with a missing or malformed part of the body has a structural birth defect. The most common types of structural defects include heart defects, spina bifida, clubfoot, cleft palate and congenital dislocated hip.

Metabolic birth defects affect a baby’s internal chemistry in a way that prevents the child’s body from breaking down food properly to create energy. Metabolic defects include a fatal disease affecting the child’s central nervous system known as Tay-Sachs disease, and phenylketonuria (PKU) which affects the body’s ability to process protein.


Birth Defects Resulting from Environmental Factors

Birth defects may be the result of environmental factors or genetic factors, or a combination of both. About 10 percent of birth defects are the result of environmental factors, according to the Physician’s Committee for Responsible Medicine, and about 20 percent are inherited. The remaining 70 percent of birth defects are of unknown etiology, which means medical scientists have not yet determined the underlying cause of the defects.
Environmental factors include smoking, alcohol consumption, exposure to radiation as a cancer treatment, the use of street drugs, and low intake of folic acid during pregnancy. Infection, such as infection with the Zika virus, can cause severe birth defects. Obesity and poor healthcare are also environmental factors that can increase the risk for birth defects.


Genetic Birth Defects

Every cell in the human body contains 46 chromosomes. Each chromosome contains thousands of genes. Each gene contains a blueprint controlling the development or function of a specific body part.

It is essential to have the right number of chromosomes for that particular body part to develop and function correctly. Having too many or too few chromosomes causes the part to receive garbled instructions about its development and function.

Since each of the genes controls the structure and function of a body part, a person with a defective gene will experience defects in the corresponding body part. Defects can affect one gene or several genes to cause a variety of birth defects.

Down syndrome is a condition caused by too many chromosomes. An accident during cell division creates an extra copy of a particular chromosome.  This extra copy typically causes a group of birth defects associated with Down syndrome, such as mental retardation, muscle weakness, a downward slant to the eyes, malformed and low-set ears, and birth defects affecting the heart and intestines.

Turner syndrome occurs when a person lacks a particular chromosome. People with Turner syndrome typically have short stature, learning disabilities, infertility and heart defects.

Genes are hereditary, which means families can pass faulty genes from one generation to the next. One such familial disorder caused by a defective gene is hemophilia, a condition where the individual lacks a chemical necessary to clot blood. Other familial gene disorders include cystic fibrosis, which causes progressive damage to the lungs and pancreas, and sickle cell anemia.

Defective genes may also be the result of accidental damage, a condition medical professionals refer to as spontaneous mutation. Accidental damage is the most common cause of achondroplasia, a condition causing extremely short stature and malformed bones.


Preventing Birth Defects

Not all birth defects can be prevented, but women can take steps to increase their chances of having a healthy baby by managing their health conditions and making healthy lifestyle choices before becoming pregnant, avoiding harmful substances during pregnancy and seeing a doctor before and throughout pregnancy..

A healthy lifestyle focuses on weight management and a sensible nutrition plan that includes folic acid, which is a type of B vitamin. Folic acid can help prevent major birth defects of the brain and spinal cord, specifically anencephaly and spina bifida. Women can get folic acid through the food they eat, particularly fortified cereals, and from supplements.

Avoiding alcohol and other harmful substances reduces the risk for birth defects. Alcohol passes from a woman’s body to her developing baby through the umbilical cord to cause miscarriage, stillbirth or a host of lifelong physical, mental and behavioral problems known collectively as fetal alcohol spectrum disorders (FASDs). Smoking can cause cleft lip or cleft palate.


OB/GYN Professionals Help Mothers Reduce the Risk for Birth Defects

Regular appointments with a physician before pregnancy and an OB/GYN specialist during pregnancy can help reduce the risk for birth defects. Regular exams help practitioners detect issues that could potentially result in problems during pregnancy.

OB/GYN practitioners can perform tests to detect chromosomal abnormalities during pregnancy. Doctors analyze cells in the mother’s placenta or fluid surrounding the babies to look for the chromosomal abnormalities that cause Down syndrome. Ultrasounds can detect some types of birth defects and your doctor may recommend chromosomal analysis to look for hereditary defects. An OB/GYN professional may run other tests, such as hCG and estradiol that can detect Down syndrome. Additionally, your doctor may collect samples of the placenta, which contains the same genetic material as the fetus, to look for signs of genetic birth defects.

OB/GYN doctors can also recommend vaccines that help protect women from infections that can cause birth defects. Most vaccines are safe for pregnant women. In fact, OB/GYN practitioners often recommend certain vaccines, such as flu vaccine and the Tdap vaccine, during pregnancy.

Healthcare professionals help women improve their overall health before and during pregnancy by offering advice on weight management, smoking cessation, avoiding alcohol and improving nutrition. For more information about the risks of pregnancy and birth defects, talk with the OB/GYN professionals at Revere Health. The obstetricians/gynecologists, certified nurse midwives and nurse practitioners at

Revere Health OB/GYN provide the full range of healthcare services that can reduce the risk for birth defects. If you are pregnant, or thinking about becoming pregnant, make an appointment with Revere Health OB/GYN.


The obstetricians/gynecologists, nurse practitioners and certified nurse midwives at Revere Health OB/GYN provide a full range of healthcare services to women throughout all stages of their lives including; puberty, child-bearing years, menopause, and beyond. 



The Live Better Team


The Live Better Team

Telehealth is not appropriate for every medical concern, so it’s important to ask your provider whether a virtual visit is suitable for your needs.

Learn more about Telehealth

This information is not intended to replace the advice of a medical professional. You should always consult your doctor before making decisions about your health.