Which hormone is secreted during parturation (childbirth)?

Oxytocin hormone is secreted during parturation (childbirth).
Oxytocin is a natural hormone that stimulates uterine contractions in childbirth and lactation after childbirth. It also affects aspects of human behaviour and the male and female reproductive systems.
Oxytocin secretion from the posterior pituitary gland is increased during parturition, stimulated by uterine contractions that forcefully expel the fetuses.