Teratogens

Below is a list of common teratogens:

SEXUALLY TRANSMITTED

Cytomegalovirus - CMV can be asymptomatic and only a small percentage of carriers will have babies with clinical symptoms.
HIV (Human Immunodeficiency Virus) and Acquired Immunodeficiency Syndrome (AIDS) - The biggest risk to the fetus is not for a difficult birth but for transmission of the virus.
Syphilis - Half of infected pregnancies will spontaneously abort. Some of those that survive may be asymptomatic, and some birth defects can be severe. Treatment during pregnancy can greatly reduce the risk to the baby.
Other sexually transmitted diseases such as Chlamydia and gonorrhea can cause blindness and infection during birth.

Rubella - Commonly known as German measles or three-day measles. Pregnancies are at increased risk for miscarriage and a high rate of serious birth defects when rubella is contracted during the first trimester. This risk diminishes with infection in the second and third trimesters.
Toxoplasmosis - This infection is transmitted by contact with undercooked pork or with cat feces. Symptoms can include prematurity, low birth weight, and birth defects. Treatment during pregnancy can improve the outcome.
Varicella - Transmitted by airborne respiratory droplets and direct contact with an infected individual’s rash. Babies infected before 20 weeks of pregnancy can be affected with congenital varicella syndrome. Exposure at the time of delivery causes infection in about 25% of exposed newborns. Infected newborns develop a rash and can die if not treated.
Other infections that can negatively affect prenatal development include influenza, chicken pox, viral hepatitis, and polio, among others.

Pollutants - lead, pesticides, PCBs, mercury, certain chemicals, and more can cause miscarriage, preterm labor and/or brain damage depending on the exposure.
Radiation- pregnant women need to avoid x-rays since repeated or mass exposure can cause brain and intellectual damage.

Stress – maternal exposure to very high stress can cause a variety of problems, from miscarriage to later brain and behavioral issues.
Malnutrition & excessive exercise can also harm fetal growth in numerous ways.

Diet & Habits – see the course for more information about the effects of legal and illegal drugs and the impact of food on the developing baby. Alcohol, tobacco, marijuana, caffeine, and other recreational drugs can cause various prenatal and birth complications and defects. Alcohol and tobacco use by pregnant women is the most preventable form of developmental teratogen exposure. Alcohol can cause Fetal Alcohol Spectrum Disorders, an umbrella term for a group of abnormalities in babies born to alcohol-consuming pregnant mothers. This includes FAS (fetal alcohol syndrome), which results from binging or drinking large amounts. Children have abnormal facial features, small heads and stature, and problems with learning. FAE (fetal alcohol effect) is now called FASD.

Certain maternal metabolic conditions like maternal diabetes and maternal phenylketonuria are associated with a raised risk of birth defects.