the time of intrauterine development, from the moment of zygote formation to the onset of labor. It usually corresponds to the duration of a full-term pregnancy and is 9 calendar months, or 40 weeks. The prenatal period includes two stages: 1) Embryonic (embryonic). 1-8 weeks of embryogenesis, divided into early and late phases.
2) Fetal (fetal). 9–40 weeks of embryogenesis, begins with the formation of the placenta. From the 9th week of embryogenesis, the developing human body is called a fetus.