when does a woman's body produce milk
Breastfeeding Changes early in pregnancy prepare the breast for lactation. Pre-birth hormone levels become altered after the birth and stimulate the production of milk. From around halfway through pregnancy, the breasts begin to produce colostrum.[17] Colostrum, a thick yellowish fluid rich in protein, continues to be produced for the first few days after delivery. Around 30 to 40 hours after delivery, the composition of milk changes to mature milk and milk volume becomes copious, an event known as the milk "coming in".[18] Sucking causes the pituitary to release oxytocin that causes to the contraction of the uterus.[19][20] Progesterone is the hormone that influences the growth of breast tissue before the birth. The postpartum changes that occur in the endocrine system after the birth shift from hormones that prevent lactation to hormones that trigger milk production.[citation needed] This can be felt by the mother in the breasts. The crying of the infant can induce the release of oxytocin from the pituitary gland.[21]