It is estimated that 10% of all birth defects are caused by prenatal exposure to a teratogenic agent. These exposures include, but are not limited to, medication or drug exposures, maternal infections and diseases, and environmental and occupational exposures.
A wide range of different chemicals and environmental factors are suspected or are known to be teratogenic in humans and in animals. A selected few include:
- Drugs and medications: tobacco, caffeine, drinking alcohol (ethanol) (see fetal alcohol spectrum disorder), isotretinoin (13-cis-retinoic acid, Roaccutane), temazepam (Restoril; Normisson), nitrazepam (Mogadon), nimetazepam (Ermin), aminopterin or methotrexate, androgenic hormones, busulfan, captopril, enalapril, coumarin, cyclophosphamide, diethylstilbestrol, phenytoin (diphenylhydantoin, Dilantin, Epanutin), etretinate, lithium, methimazole, penicillamine, tetracyclines, thalidomide, trimethadione, methoxyethyl ethers, Flusilazole, valproic acid, and many more.
- Environmental chemicals: polycyclic aromatic hydrocarbons (polynuclear aromatic hydrocarbons), polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins a.k.a dioxin, polychlorinated dibenzofurans (PCDFs), hexachlorobenzene hexachlorophene, organic mercury, ethidium bromide, etc.
- Ionizing radiation: atomic weapons fallout (Iodine-131, uranium), background radiation, diagnostic x-rays, radiation therapy
- Infections: cytomegalovirus, herpes virus, parvovirus B19, rubella virus (German measles), syphilis, toxoplasmosis, Venezuelan equine encephalitis virus. (An easy way to remember maternal infections is TORCH: Toxoplasmosis, Other agents, Rubella, CMV and HSV.
- Metabolic imbalance: alcoholism, endemic cretinism, diabetes, folic acid deficiency, iodine deficiency, hyperthermia, phenylketonuria, rheumatic disease and congenital heart block, virilizing tumors
Most of teratogen-caused birth defects are potentially preventable and Public Health should carefully scrutinize and ban any suspect chemical.