What are teratogens?

Exposures during pregnancy that can harm the developing fetus and exposures through breast milk that are harmful for the baby.

What is teratology?

The study of birth defects caused by exposures during pregnancy.

What are some common teratogens?

Teratogens are any exposure, not just medications, which can be harmful. Some examples of teratogens are:

  • Medications: Ace Inhibitors, Carbamazepine, Isotretinoin, Lithium, Tetracycline, Thalidomide, Warfarin, Valproic Acid
  • Maternal Conditions: Diabetes mellitus, Phenylketonuria (PKU), Iodine Deficiency, Severe Obesity
  • Maternal Infections: Rubella, Syphilis, CMV, Toxoplasmosis
  • Other Exposures: Alcohol, Radiation, Heat, Hypoxia, Trauma, Lead, Mercury
  • Illicit Substances: Cocaine, Heroine

For more information about these and other teratogens check out these fact sheets.

Who will I be speaking with when I call Texas TIPS?

Specially trained genetic counselors answer the phone at Texas TIPS. To find out more about what genetic counselors are, visit the National Society of Genetic Counselors website.

What resources does Texas TIPS use?

To find the most up-to-date information, Texas TIPS uses a variety of resources, such as research and review articles, textbooks and online databases. Also, since Texas TIPS is located within the McGovern Medical School at UTHealth, we have access to a network of physicians in a variety of disciplines to aide us in specific questions. As needed, Texas TIPS also uses local and national resources, such as Poison Control, CDC, OTIS and others.

Should I only worry about exposures in the first trimester?

The first trimester of pregnancy is when the baby is developing and forming its body parts. Although exposures during this time have the potential to interfere with development and cause birth defects, this is not always the case. Each exposure is different in how and at what point in the pregnancy it can affect the baby. Some exposures only affect the baby in the second or third trimesters, while others have the potential to affect the baby at any point in the pregnancy. For more information about specific exposures, contact Texas TIPS.

If I think I might have exposed my baby to a teratogen, what should I do?

If there is a possibility that your pregnancy has been exposed to a teratogen, it’s important to stay calm. Gather information about the exposure, such as: name, dose/amount, duration (e.g. how many times did exposure occur) and route of exposure (e.g. oral, IV, topical). With this information, either contact Texas TIPS  or call and make an appointment with your OB/GYN.