5 of the Most Common and 4 Surprising Causes of Birth Defects

A birth defect, also called a congenital anomaly, is a problem that occurs when a baby is developing in the womb. An estimated one out of every 33 babies in the U.S. is born with a birth defect, of varying severity, according to the Centers for Disease Control and Prevention.

If you’re a parent-to-be, or planning to be, it’s important to understand what causes birth defects and the steps you can take to prevent them during pregnancy.

5 of the Most Common Causes of Birth Defects

Here’s an overview of the most common causes of birth defects:

• Genetics: A genetic abnormality occurs when genetic material (e.g., chromosomes, genes) is extra, missing or mutated. It can happen spontaneously, or the mother or father can pass this on to their baby. It happens at conception and, unfortunately, usually can’t be prevented. The risk of this type of abnormality is higher if you’re over 35, or you or your partner have a family history of genetic defects. Genetic testing can help identify your specific risks.
• Lifestyle behaviors: Smoking, alcohol, and illegal and legal drug use increase the risk of birth defects. Even though marijuana is now legal in Massachusetts, you should avoid it while you’re trying to conceive and during pregnancy.
• Certain medications and chemicals: While numerous medications are associated with birth defects, never stop taking any prescribed drug without first talking to your doctor. Many drugs can be swapped out for something safer. If you work with or around chemicals, your employer should adhere to OSHA-mandated safety guidelines, which may require you to use protective equipment, such as a mask and gloves.
• Infections during pregnancy: A number of infections (such as rubella or German measles) can cause congenital anomalies. Some of which can be vaccinated against. Sexually transmitted diseases can also harm a developing fetus.
• Medical conditions: Diabetes is a common condition that, if not tightly controlled, can increase the risk of birth defects.

4 Surprising Causes of Birth Defects

There are also some lesser-known, even surprising, causes of birth defects that you should be aware of:

• Christmas lights: Christmas lights are loaded with lead, which is used in PVC wiring to prevent cracking and as a flame retardant. You can be exposed by touching the lights and breathing lead dust. High levels of lead during pregnancy can cause miscarriage and stillbirth; even exposure to small amounts of lead may cause mild learning disabilities in a child. Pregnant women (and children) should not handle these lights. If you do, wash your hands immediately, and dust areas around the lights using a disposable wet cloth.
• Cat feces: While it’s fine to be around cats when you’re pregnant, it’s best to have someone else clean the litter box. Cat feces can carry a parasitic infection called toxoplasmosis. If you get this infection while pregnant, or even a few months before you conceive, it can cause serious birth defects such as eye and brain damage. If you’re the only one who can clean the litter box, do it daily (the parasite isn’t infectious for one to five days). Use disposable gloves (throw them away after each use), then wash your hands well with soap and water.
• Pet rodents: Mice, hamsters and guinea pigs may be cute, but they may carry a virus called lymphocytic choriomeningitis (LCMV) that can cause severe birth defects and miscarriage. Keep pet rodents in a separate part of your home, wash your hands after touching them, and ask other family members to clean the cage (and to do so in a well-ventilated area or outside).
• Pet birds: People can get a bacterial disease called psittacosis from birds; it’s most commonly found in parrot-type birds such as cockatiels, parakeets, cockatoos and macaws. You can become infected when you breathe dust from dried bird droppings or nasal secretions. Once again, you should thoroughly wash your hands with soap and water after you touch birds or their droppings, and clean cages daily so droppings don’t dry out and become airborne. Better yet, have someone else do it!

Given that 50% (that’s right, half!) of pregnancies are unplanned, it’s important to follow these preventive steps regardless. And if you’re planning to have a baby, it’s a good idea to schedule an appointment with an Ob/Gyn to review the medications you’re taking, any medical conditions you have, your potential for job-related exposures, and other factors you can control to decrease the risk of birth defects.

Another proactive move you can make is to start taking folic acid supplements. They help prevent neural tube defects, which can result in brain and spine abnormalities. Taking a daily multivitamin is also a good idea to make sure your body gets all the necessary nutrients and vitamins to nourish a healthy baby.

And helping you deliver a healthy baby is our #1 priority.

Guest Blogger: Tiffany Moore Simas, MD, MPH, MEd, Vice Chair, Department of Obstetrics and Gynecology, UMass Memorial Health Care