Developmental Stages

Learn about the stages of development, their definitions, and the physical; cognitive; and emotional, cultural, and social development associated with each.


Pre•na•tal \ ()prē-nā-təl\


Definition: occurring, existing, or performed before birth <prenatal care> (Merriam-Webster Online)

Conception to Birth

Physical Development

  • Nature and nurture are both important in the development of all stages of human life.  Nurture, that is, environmental factors, such as good nutritional intake by the mother and the avoidance of toxins, significantly affect prenatal health. Nature, or genes that may cause disorders, also influence prenatal development.
  • We start as a single cell that contains all the genetic information that we will need for our entire life.  From that single cell, 350 different cell types will be formed prior to birth.
  • Prenatal development spans three stages. Gestation begins with conception and lasts until the fertilized egg is implanted in the uterus (around two weeks). The embryonic stage marks the development of the major organs and limbs (two weeks to ten weeks after conception). The fetal stage lasts from the eleventh week to birth.  During this stage the development of all organs continues and the fetus grows in size and weight.
  • Environmental factors pose risks at different stages of development. For example, the embryo is particularly vulnerable to the effects of German measles (rubella). The mother’s infection by the virus during the first month of pregnancy leads to an almost 50% chance of infant blindness or brain damage. The percentage drops to 22% if contracted in the second month and decreases thereafter.

Cognitive Development

  • Executive function refers to a variety of interdependent skills that are necessary to perform goal-directed activities such as making plans and purposefully integrating past knowledge and present information. It had been believed that such skills were not expressed until later in our development, such as during adolescence. However, evidence indicates that cognition begins to develop as early as in the womb.
  • Our cognitive development is influenced by our prenatal environment.  A healthy fetus requires oxygen, protein and micronutrients. Conversely, the absorption of toxins such as alcohol, lead and tobacco can have negative neurological effects that last a lifetime.
  • The baby’s physical environment has the strongest effect on its prenatal development. There is no evidence that non-physical stimuli such as exposing the baby to classical music in utero will raise a child’s IQ.

Next: Infant