Embryology- is the cience of the development of an embryo from the fertilization of the ovum to the fetus stage.
A zygote is created by the fertilization of two haploid cells created by meiosis. Because a zygote is fertilized by two haploid cells, it is diploid. It then has to divide and grow through mitosis like any other body cells.
What is a teratogen? A teratogen is an agent, which can cause a birth defect. It is usually something in the environment that the mother may be exposed to during her pregnancy. It could be a prescribed medication, a street drug, alcohol use, or a disease present in the mother which could increase the chance for the baby to be born with a birth defect. About 4 percent to 5 percent of birth defects are caused by exposure to a teratogen.
Alcohol- A woman who drinks alcohol while she is pregnant may harm her developing baby (fetus). Alcohol can pass from the mother’s blood into the baby’s blood. It can damage and affect the growth of the baby’s cells. Brain and spinal cord cells are most likely to have damage. The term "fetal alcohol spectrum disorder" (FASD) describes the range of alcohol effects on a child. The problems range from mild to severe. Alcohol can cause a child to have physical or mental problems that may last all of his or her life.
Cocaine- Cocaine use during pregnancy can affect a pregnant woman and her unborn baby in many ways. During the early months of pregnancy, it may increase the risk of miscarriage. When the drug is used late in pregnancy, it may trigger premature labor. It also may cause an unborn baby to die or to have a stroke, which can result in irreversible brain damage.
Women who use cocaine during pregnancy are: twice as likely to have a premature baby; More likely to have a low birth-weight baby; More likely to have babies born with smaller heads and smaller brains proportionate to body size.
