Snapshot A 27-year-old woman visits her physician a month before embarking on a safari trip to sub-Saharan Africa with her partner. Her doctor prescribes her doxycycline for malaria prophylaxis, and the patient takes the medication daily as instructed. A month after returning from her trip, the women discovers that she is pregnant. Her baby is born via vaginal delivery 9 months later and is found to have teeth discoloration, as seen in the image. Introduction Overview teratogens are agents that can cause abnormal fetal development and birth defects effects vary depending on timing of fetal exposure to the teratogen weeks 1-3 of gestation "all-or-none" effects the embryo either dies or survives without any complications weeks 3-8 of gestation embryonic period most susceptible time period due to organogenesis week 8 of gestation until birth growth and function of organs are affected TeratogensSubstance AbuseTeratogenEffects on FetusAlcoholFetal alcohol syndromeCocaineLow birth weightPreterm birthIntrauterine growth retristrictionPlacental abruptionNicotineLow birth weightPreterm laborPlacental problemsSudden infant death syndromeADHDMedicationsACE inhibitors (i.e.,lisinopril)Renal damagerenal dysplasiaAlkylating agents (i.e.,cyclophosphamide)Absence of digitsCleft palateRenal agenesisAminoglycosides (i.e.,gentamicin)OtotoxicityAntiepileptic drugs (i.e.,phenytoin)Neural tube defectsCardiac defectsCleft lip and palateDiethylstilbestrolVaginal clear cell adenocarcinomaCongenital cervical, ovarian, and uterine abnormalitiesFolate antagonists (i.e.,methotrexate)Neural tube defectsmeningomyeloceleIsotretinoinMultiple severe birth defects (i.e.,cleft palate, microphthalmia, and congenital heart defects)LithiumEbstein anomalyMethimazoleAplasia cutis congenitaTetracyclines (i.e., doxycycline)Discolored teethInhibited bone growthThalidomideLimb defectsWarfarinBone deformitiesFetal hemorrhageAbortionOphthalmologic abnormalities