What period is referred to as the preembryonic stage?

The preembryonic stage refers to the time frame from conception until the end of the second week of gestation, specifically encompassing the initial two weeks after fertilization. During this critical period, significant processes such as fertilization, cell division, and the formation of the blastocyst occur. This stage is foundational as it lays the groundwork for the subsequent embryonic and fetal development.

The subsequent stages indicate different developmental processes. From 14 days to 6 weeks represents the embryonic stage, where the major organs and structures begin to form. The 6 weeks to 3 months period is characterized as the early fetal stage, where further maturation of the organs occurs. Finally, the stage from 3 months to birth focuses on the growth and maturation of the fetus until delivery. Each of these stages has distinct features and developmental milestones that are critical for understanding human development.