Fetal Period (Third Month To Birth)
- Fetal period extends from the beginning of 3rd month to the end of intrauterine life (till birth). It is the period of maturation of tissues and organ and rapid growth of body occurs. By the end of organogenesis (end of embryonic period) most of the organ systems are developed, however, the function of roost of them is negligible except cardiovascular system (cardiovascular system is first to function.
- During fetal period all organs are matured (which are developed during embryonic period). Main characteristics of fetal period of development are:
- Body growth is very period.
- Differentiation of tissues occurs rapidly leading to maturation of organ system.
- Growth in length is particularly striking during 3rd, 4th and 5th month.
- Weight of the fetus increases rather slow during first half of intrauterine life. The weight increases considerably during second half of intrauterine life.
- Head growth is peculiarly slow compared to the growth of rest of the body during whole of fetal period.