At which developmental stage can the skin be noted as transparent and external genitalia can first be identified?

The correct response focuses on the fetal development stage, which typically occurs from around eight weeks after conception until birth. During this period, significant growth and maturation of the fetus take place, including the development of skin and external features.

Around the end of the first trimester and into the second trimester, the skin begins to show characteristics such as being thin and somewhat transparent, which allows for the visibility of underlying structures like blood vessels. Additionally, it is during this time that external genitalia become distinguishable, allowing healthcare providers to identify the sex of the fetus through ultrasound. This stage is crucial for the formation and differentiation of bodily systems, including integumentary structures.

Conception covers the initial moment of fertilization, while embryonic development refers to the period from conception to about eight weeks, where foundational systems form but before the full formation of recognizable external features. Neonatal development pertains to the time after birth, where the newborn continues to grow and adapt outside the womb. Thus, the details of skin transparency and identification of external genitalia specifically align with the events that occur during fetal development.