Which of the following are the stages of fetal development?

The stages of fetal development are best described by the pre-embryonic, embryonic, and fetal stages. This classification is important for understanding the progression of development that occurs from conception until birth.

In the pre-embryonic stage, which lasts until approximately the end of the second week after conception, the fertilized egg undergoes rapid cell division and forms a blastocyst. During this stage, implantation occurs in the uterine wall.

The embryonic stage follows and lasts from the third to the eighth week of gestation. This is a critical phase during which the major organ systems begin to develop and the foundations of the body structure are laid down. It is a sensitive period where the embryo is most vulnerable to teratogenic influences.

Finally, the fetal stage starts from the ninth week of gestation until birth. During this stage, the developing fetus undergoes growth and maturation of organs, with an emphasis on increasing size and functional capability.

This structured progression clearly outlines the key phases of development in utero and underlines the significant developmental milestones that occur during each stage, making the option referring to these stages the correct choice.