Normal delivery involves the natural process of a baby passing through the birth canal. Reproduction is a natural process that allows organisms to produce offspring through the fertilization of male and female gametes in the womb. A human pregnancy involves stages as the zygote grows into a fetus inside the uterus until birth. A planned pregnancy allows for monitoring of the mother's health and delivery of guidelines for vitamins, diet, and lifestyle. Normal vaginal delivery occurs when the cervix dilates and the baby passes head first through the vagina, with the shoulders and body following, over 12-16 hours of labor monitored by an obstetrician.