Common infections that may be teratogenic include Herpes simplex Viral hepatitis Rubella Varicella Syphilis Toxoplasmosis Cytomegalovirus infection Coxsackievirus infection Zika infection Commonly used drugs that may be teratogenic include Alcohol Tobacco Cocaine Some prescription drugs (see table Drugs With Adverse Effects During Pregnancy) Hyperthermia or exposure to temperatures > 39° C (eg, in a sauna) during the 1st trimester has been associated with spina bifida.