Teratogen

Definition

A teratogen is any substance, organism, or environmental agent that can cause abnormal fetal development when exposure occurs during pregnancy.

Common Teratogens

• Medications: Warfarin, ACE inhibitors, isotretinoin (Accutane), thalidomide, lithium, valproate, methotrexate, phenytoin, tetracyclines, live vaccines (MMR, varicella).
• Substances: Alcohol (fetal alcohol syndrome), tobacco, cocaine, methamphetamine.
• Infections: TORCH (Toxoplasmosis, Other, Rubella, CMV, Herpes), Zika.
• Radiation: Ionizing radiation.
• Maternal conditions: Uncontrolled diabetes, PKU.

Highest Risk Period

Organogenesis (weeks 3 to 8 gestation) when organs are forming. Many pregnancies are not yet recognized at this time. Preconception counseling is ideal.

Nursing Interventions

Review all medications and exposures with pregnant patients, such as advise against alcohol, smoking. Vaccinate before pregnancy. Teach folic acid 400 to 800 mcg daily before conception.

NCLEX Relevance

ACE inhibitors and warfarin contraindicated in pregnancy.