Birth Defects: What They Are and How to Prevent Them

Birth defects can be scary and stressful but there are ways to prevent them before becoming pregnant. Read more to find out how to have a healthy pregnancy.
Birth Defects: What They Are and How to Prevent Them

Last update: 16 November, 2020

Birth defects are genetic or physical anomalies that occur while the fetus is developing in the mother’s uterus. In order for doctors to diagnose it as a congenital disorder, these anomalies have to be present at birth.

The majority of birth defects happen in the first trimester of pregnancy and are detected early on through routine screenings. Other defects are detected later on during pregnancy, at birth, or during childhood.

These types of anomalies can alter the fetus’ anatomical structure or proper organ function, though the severity varies case by case.

Babies born with minor anomalies can go on to live a healthy life. On the other hand, more serious birth defects can result in lasting disabilities or require chronic treatment, including surgery throughout childhood.

Finally, some birth defects are terminal and result in miscarriage or death shortly after birth.

Genetic causes

Unfortunately, the majority of birth defects detected in embryos, fetuses, or newborns cannot be linked to a specific cause. For those that can, oftentimes genetic factors are the cause. Below are some of the most common genetic causes of congenital anomalies:

  • Chromosomal abnormalities: these occur due to an error in the chromosomes of the egg or sperm, resulting in an abnormal number of chromosomes, a broken chromosome, or a missing chromosome. An example of a chromosomal abnormality is Down Syndrome.
  • Genetic anomalies: in these cases, a specific gene is altered. Genetic anomalies can be hereditary or caused by damage to genes during fertilization. Some examples are achondroplasia, cystic fibrosis, or phenylketonuria.
  • Polygenic abnormalities: genetic disorders caused by multiple combined genetic and chromosomal alterations. Examples are spina bifida, anencephaly, cleft lip, or congenital hip dislocation.

Environmental causes

Now, we’ll tell you about the external causes that can generate a congenital defect to the embryo or fetus:

  • Maternal health issues: can disrupt healthy fetal development and cause birth defects. Some examples are women with diabetes who can’t get their glucose levels under control, women with hypertension who can’t control their blood pressure, or women with hypothyroid issues who aren’t adequately medicated.
  • Environmental illnesses: illnesses and toxins women can come into contact with during pregnancy can affect fetal development. For example, rubella, toxoplasmosis, syphilis, and chickenpox.

Plan and prevent

Planning a healthy pregnancy is possible. These are simple steps a woman can take to lower the risk of her baby having a birth defect:

  • Take folic acid: by taking a 400 microgram dose every day during a 30-90 period before planning to get pregnant, and continuing throughout at least the first trimester, mothers can significantly lower the risk of anomalies in the brains and spines of their babies. Additionally, there is a wide variety of food rich in folic acid.
Folic acid to prevent birth defects.

  • Avoid alcohol: a steadfast rule for pregnant women is to not drink alcohol at all during pregnancy, in any trimester. No alcoholic beverage is safe for an embryo or fetus.
  • Stay away from tobacco: studies show tobacco and nicotine can cause premature births and cleft lip or palate. Pregnant women should neither smoke nor be around other people who are smoking.
  • Don’t use recreational drugs: cocaine, marijuana, and ecstasy can affect fetal development. These drugs can cause low birth weight and major birth defects in the urinary tract and heart.
  • Carefully check non-prescription medications: there are plenty of medications that are unsafe for use during pregnancy as they can cause birth defects. If you’re pregnant, always check with your doctor before taking any medication.

The importance of medical care during pregnancy

Medical care before and during pregnancy is crucial. Doctors have the training necessary to detect, diagnose, and treat congenital abnormalities.

Likewise, doctors are also able to give medical advice to help prevent birth defects. Below are two important pieces of advice doctors would give to a woman planning to become pregnant or already pregnant:

Couple talking with their doctor about pregnancy.

  • Stay up-to-date on vaccines: during pregnancy, it’s imperative to be up to date on the vaccine schedule and follow your doctor’s indications about which vaccines they recommend.
  • Be aware of maternal illnesses: both pre-existing illnesses and ones that can happen during pregnancy like gestational diabetes, hypertension, or hyperthyroidism, should be under careful observation so they don’t affect the fetus’ development.
It might interest you...
5 Ways To Increase Folic Acid Intake During Pregnancy
Step To HealthRead it in Step To Health
5 Ways To Increase Folic Acid Intake During Pregnancy

In this article, you'll discover how to increase your folic acid intake during pregnancy. Of course, you should talk to your doctor before making a...

  • Einstein, A., B. Podolsky, and N. Rosen, 1935, “Can quantum-mechanical description of physical reality be considered complete?”, Phys. Rev. 47, 777-780.
  • Sanfélix Gimeno G., Ferreros I., Librero J., Peiró S. Caracterización de la suplementación de folatos en el embarazo a partir de la combinación de sistemas de información sanitaria. Gaceta Sanitaria. 2012. 26:512-8.
  • Morales Peralta Estela. Birth defects in pediatric practice. Rev Cubana Pediatr  [Internet]. 2016  Mar [citado  2019  Jun  14] ;  88(1). Disponible en:
  • Raoul C. Hennekam, Leslie G. Biesecker, Judith E. Allanson, Judith G. Hall, John M. Opitz, I. Karen Temple, John C. Carey, Elements of Morphology Consortium
  • Am J Med Genet A. 2013 Nov; 161A(11): 2726–2733. Published online 2013 Oct 3. doi: 10.1002/ajmg.a.36249