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Doctors give trusted, helpful answers on causes, diagnosis, symptoms, treatment, and more: Dr. Ferguson on at what stage are teratogens the most dangerous during pregnancy: During the first trimester (12 to 14 weeks) the fetus is developing rapidly with rapid cell division which is very sensitive to teratogens.


Some teratogens are benign until they build to "threshold concentration" levels in the mother and then their effects are seen. Some teratogens are dangerous throughout a pregnancy and some are dangerous only at specific points of embryonic development. The only safe course of action is to actively avoid known teratogens before and during pregnancy.


Teratogens are drugs, chemicals, or even infections that can cause abnormal fetal development. There are billions of potential teratogens, but only a few agents are proven to have teratogenic effects.


TERATOGENS AND THEIR EFFECTS. 23-2 There are a variety of causes of congenital malformations including: 1) genetic factors (chromo- ... tibility to teratogens. The most critical period in the development of an embryo or in the growth of a ... Binge drinking also likely has a harmful effect on embryonic brain developments at all times of gestation.


à other teratogens are harmful at any time during the pregnancy---for example, for behavioral teratogens, there is no safe period---the brain and nervous system can be harmed throughout the pregnancy . critical period---in prenatal development, the time when a particular organ or other body part is most susceptible to teratogenic damage


A teratogen is any agent that causes abnormalities when a developing baby is exposed to it during the mother's pregnancy. These "environmental exposures" can cause birth defects and other problems. Teratogens are can have effects that range from mild to severe, and they are often most dangerous during early pregnancy and with excessive or prolonged exposure.


Some viruses can have ill effects on the fetus if the mother-to-be becomes infected. The varicella virus is a teratogen that many mothers-to-be worry about, because chicken pox during pregnancy can be complicated and dangerous. Thankfully, chicken pox infection is rare, occurring in only about 1 out of every 2,000 pregnant women; 90 percent of pregnant women in the United States are immune to ...


Most teratogens are harmful only during a critical window of development (e.g., thalidomide is teratogenic only between days 28 and 50 of pregnancy). Teratogenic agents inhibit specific receptors or enzymes or disrupt specific developmental pathways (e.g., some agents show neurotropism or cardiotropism). Effects of teratogens are dose-dependent.


Teratogens Overview What is a teratogen? A teratogen is an agent that can cause or increase the chance of 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, chemical exposure, or an infection present in the mother ...


Teratogens 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 ...