Childbirth (also called labo(u)r, birth, partus or parturition) is the culmination of a human pregnancy with the emergence of a newborn infant from its mother's uterus.

First stage: contractions A typical human childbirth will begin with the onset of contractions of the uterus. The frequency and duration of these contractions varies with the individual. The onset of labour may be sudden or gradual, and is defined as regular uterine activity in the precence of cervical dilatation. A gradual onset with slow cervical change towards 3 cm (just over 1 inch) dilation is referred to as the "latent phase". A woman is said to be in "active labour" when contractions have become regular in frequency (3-4 in 10 minutes) and

Many governmental strategies and international initiatives have promoted breastfeeding as the best method of feeding a child in his or her first year. So do the World Health Organization (WHO), the American Academy of Pediatrics (AAP), and many others.

about 60 seconds induration. The now powerful contractions are accompanied by cervical effacement and dilation greater than 3 cm. The labour may begin with a rupture of the amniotic sac, the paired amnion and chorion ("breaking of the water"). The contractions will accelerate in frequency and strengthen. In the "transition phase" from 8 cm–10 cm (3 or 4 inches) of dilation, the contractions often come every two minutes are typically lasting 70–90 seconds. Transition is often regarded as the most challenging and intense for the mother. It is also the shortest phase.