Correct Answer - Option 4 : embryo and fetus only
Prenatal development is the process in which an embryo or fetus, gestates during pregnancy, from fertilization until birth.
- A teratogen is any agent or factor to which embryo-fetal exposure produces a permanent alteration in the form or function of the offspring. Of prime importance is the time period in pregnancy during which there was fetal exposure. For this purpose, gestation is divided into three periods. They are:
- Fertilization to implantation
- Embroynic period
- Fetal period (9th week till term)
- It is an external agent that affects the development of fetus and embryo.
- The classic teratogenic risk period in human beings lasts from approximately 31 days after the last menstrual period (LMP) or a few days after missed periods through 10 weeks from LMP.
Thus, it is concluded that A teratogen is an external agent, such as a chemical, virus, or type of radiation that can adversely affect the development of the embryo and fetus only.
- The terms embryo and fetus both refer to the developing baby inside the mother’s womb (uterus).
- The distinction between embryo and fetus is made based on gestational age.
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An embryo is the early stage of human development in which organs are critical body structures are formed.
- An embryo is termed a fetus beginning in the 11th week of pregnancy, which is the 9th week of development after fertilization of the egg.
