What are teratogens and their effects?
What are teratogens and their effects?
A teratogen is something that can cause birth defects or abnormalities in a developing embryo or fetus upon exposure. Teratogens include some medications, recreational drugs, tobacco products, chemicals, alcohol, certain infections, and in some cases, health problems such as uncontrolled diabetes in pregnant people.
What is teratogenic effects in 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. These effects can result in a baby being born with a birth defect.
What disorders can teratogens cause?
Some experts include syphilis as a teratogen. HIV is not a teratogen. Maternal illnesses: Diabetes mellitus….Maternal infections:
- Rubella virus.
- Cytomegalovirus (CMV).
- Toxoplasmosis.
- Herpes simplex virus.
- Varicella virus (chicken pox and herpes zoster).
What are examples of teratogenic effects?
These include cleft palate, heart defects, abnormalities of the outer ears, and underdevelopment of the lower jaw. Isotretinoin is also linked with neural tube defects. Some types of tranquilizers, such as phenothiazine and lithium, are thought to be teratogens.
When are teratogens 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. Genetics: Sometimes, the pregnant person’s or the baby’s unique genetics protect them or make them more vulnerable to certain teratogens.
When a drug is teratogenic What is the risk for harm to the fetus?
Drugs reaching the fetus during this stage may cause a miscarriage, an obvious birth defect, or a permanent but subtle defect, that is noticed later in life. At 9th week the embryo is referred to as a fetus. Development during this time is primarily maturation and growth.
When do teratogens have their 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.
When is the most serious damage from teratogens likely to occur?
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.
Can teratogens cause miscarriage?
Effects of teratogens during this period of developmental often times results in an “all or none effect.” That is, the effect of the teratogen, if it is to have any effect, will be so profound as to cause a spontaneous abortion.
How do teratogens cause birth defects?
As a baby grows in the womb, teratogens may affect parts of the baby’s body as they are forming. For example, the neural tube closes in the first 3 to 5 weeks of the pregnancy. During this time, teratogens can cause neural tube defects such as spina bifida.
When do teratogens have the most serious effects on fetal development?
Why are teratogens harmful?
Types. The impact of teratogens on pregnancy or a fetus depends on several factors.
What are considered teratogens?
– Physical teratogens – Chemical teratogens – Maternal metabolic conditions – Infectious teratogens
How does the FDA classify teratogenic drugs?
– Risk Summary – Clinical Considerations – Data
What are teratogenic effects?
Teratogens act via a specific mechanism on developing cells and tissues to initiate a cascade of altered developmental events. Teratogenic effects are dependent on the nature of the teratogen, including chemical properties of the chemical, route of exposure, maternal/fetal bioactivation, placental transport, etc.
