ANATOMY

Detailed explanation-1: -Normal prenatal development lasts about 38 weeks and is divided into three stages: germinal, embryonic, and fetal. During these three stages of gestation, the original single-celled zygote develops into an embryo and then fetus [1, 2].

Detailed explanation-2: -The first stage is the germinal stage when cell division takes place. The second stage is gastrulation which is when the germ layers will develop, followed by neurulation during which the nervous system starts to develop. Lastly, organogenesis is the stage when the organs develop.

Detailed explanation-3: -The process of embryonic development is called embryogenesis. In assisted reproduction treatments, the first signs of embryonic development take place in the laboratory, during embryo culture, when the egg is fertilized and becomes a zygote. Pre-embryonic period: what an embryo looks like during its first weeks of life.

Detailed explanation-4: -Defining the Fetal Stage A fetus is a prenatal human being between the embryonic stage and birth. The fetal stage extends from the beginning of the ninth week after fertilization to about 38 weeks after fertilization, which is the average time of birth. The fetal stage lasts a total of approximately 30 weeks.

Detailed explanation-5: -The embryonic period is all about the formation of important systems of the body. Think of it as your baby’s basic foundation and framework. The fetal period, on the other hand, is more about growth and development so your baby can survive in the outside world.