ABSTRACT
This chapter presents a brief survey of physiological, biochemical, and behavioural aspects of labor and delivery in representative species, in order to elucidate the differences between birth in human and nonhuman primates. It offers cross-cultural comparisons to present the universal and particularistic aspects of birth in the human species. Labor in human beings is divided into three stages. The first stage is the period during which cervical dilation takes place. During the second stage of labor, the fetus completes its descent through the pelvis and is expelled from the uterus. The third stage begins at delivery and ends when the placenta is expelled. The purpose oxytocin during parturition is the stimulation of uterine contractions that lead to delivery of the fetus. Medication is often cited as a factor affecting length of labor and outcome in human deliveries. In twentieth century, providing obstetrical medication for human females in labor and delivery was a normal part of giving birth in a hospital.
