TERATOGENS~~

teratogens means any agent that can disturb the development of an embryo or fetus. Teratogens may cause a birth defect in the child. Or a teratogen may halt the pregnancy outright. The classes of teratogens include radiation, maternal infections, chemicals, and drugs.

alcohol.
-19% drink alcohol during precnancy,use may be catastriphic
-results in cell disruption, cell death, and decrease blood flow to fetus.
-cognitive and behavioral effects: major cause of mental radiation, impulsivity, distractibility, hyperactivity.
-fetal alcohol syndrom - overall growth deficiency, head and facial malformations.

cocaine
-retards fetal groth: associated with malformations in brains, intestines, genital-urinary tract.
-behavioral effects include increase irritability, muscle tremors, rigidity, decrease spontaneous movement, arausal dysfunction

cigarettes
-12% of pregnant women smoke
-450 chemicals in smoke with direct, indirect effects.
-both smoker and fetus gain less weight
-low birth weight, behavioral effects

maternal diseases
-infection disease endanger fetus
-readily cross placental barrier; may cause birth defects or death.
-herpes simplex may be transmitted at birth