When do teratogens have the greatest effects?
The embryonic period, during which organogenesis takes place, occurs between implantation at around 14 days to around 60 days postconception. This is usually the most sensitive period to teratogenesis when exposure to a teratogenic agent has the greatest likelihood of producing a malformation.
In which period are teratogens the most harmful?
Time of exposure: Teratogens are most harmful early in pregnancy, starting about 10 to 14 days after conception to about 8 weeks into pregnancy.
What trimester is most vulnerable to teratogens?
During the development of a baby, there are certain organs forming at certain times. If a teratogen has the potential to interfere with the closure of the neural tube, for example, the exposure to the teratogen must occur in the first 3.5 to 4.5 weeks of the pregnancy, since this is when the neural tube is closing.
During what phase of pregnancy is exposure to a teratogen likely to do the most damage?
The developing child is most at risk for some of the most severe problems during the first three months of development. Unfortunately, this is a time at which many mothers are unaware that they are pregnant. Today, we know many of the factors that can jeopardize the health of the developing child.
Is caffeine a teratogen?
In humans, caffeine does not present any teratogenic risk. The increased risk of the most common congenital malformations entailed by moderate consumption of caffeine is very slight.
What are 4 teratogens?
Teratogens are classified into four types: physical agents, metabolic conditions, infection, and finally, drugs and chemicals.
Is stress a teratogen?
Maternal psychological stress has essentially been conceptualized as a teratogen, that is, an agent that can generate deleterious perinatal and/or developmental outcomes.
What birth defects can teratogens cause?
During this time, teratogens can cause neural tube defects such as spina bifida. Some organs are sensitive to teratogens during the whole pregnancy. This includes the baby’s brain and spinal cord. Alcohol affects the brain and spinal cord, so it can cause harm at any time during pregnancy.
What are 2 common teratogens?
Teratogenic agents include infectious agents (rubella, cytomegalovirus, varicella, herpes simplex, toxoplasma, syphilis, etc.); physical agents (ionizing agents, hyperthermia); maternal health factors (diabetes, maternal PKU); environmental chemicals (organic mercury compounds, polychlorinated biphenyl or PCB.
What are teratogens give 5 examples?
Common teratogens include some medications, recreational drugs, tobacco products, chemicals, alcohol, certain infections, and in some cases, uncontrolled health problems in the birthing parent. Alcohol is a well-known teratogen that can cause harmful effects on the fetus after exposure at any time during pregnancy.
What teratogen is most likely to affect pregnancy?
The most common malformations include craniofacial dysmorphisms, cleft palate, thymic aplasia, and neural tube defects. The tranquilizer thalidomide is one of the most famous and notorious teratogens.
Is the flu virus a teratogen?
However, a direct teratogenic effect from influenza viruses appears to be unlikely, and we suggest that the higher prevalence of the CAs indicated above can be explained mainly by fever, because this risk was reduced by the use of antifever drugs.
Which virus can cause teratogenic effects?
Rubella. Rubella is one of the more teratogenic viruses.
Can viruses affect fetal development?
Viruses rarely cross the placental barrier, but when the virus does reach the fetus, it can result in severe birth defects such as microcephaly or even fetal death.
What diseases are teratogenic?
Five viruses are known to be teratogenic in humans: cytomegalovirus, rubella, herpes simplex, Venezuelan equine encephalitis, and varicella viruses.
What country has the highest rate of birth defects?
According to the report, Sudan has the most birth defects, with 82 per 1,000 live births, compared with 39.7 in France, which had the lowest number among the 193 countries surveyed.
What is the number 1 birth defect?
The most common birth defects are: heart defects. cleft lip/palate. Down syndrome.
What race has the most deformities?
American Indians had the highest rates of lethal birth defects, followed by Asians, Hispanics, and blacks. The variation in rate of lethal birth defects among racial/ethnic groups may have been related to both incidence and survival.