Milk production begins during pregnancy and continues after birth in different stages:
- During pregnancy, milk production starts around the midpoint, between weeks 16 and 22. This early milk is called colostrum, a yellowish, nutrient-rich milk that contains antibodies and serves as baby’s first food after birth. Some women may notice colostrum leaking during the second or third trimester, but this is not always the case.
- After birth, colostrum is available in the first 24 hours and lasts for a few days.
- Transitional milk, which is a mix of colostrum and mature milk, usually starts coming in between days 3 and 5 postpartum and lasts up to two weeks.
- Mature breast milk typically comes in around the end of the second week after birth (about 7 to 15 days postpartum). It is the milk that will be produced for the remainder of breastfeeding, adapting in composition to the baby’s needs.
Signs that milk is coming in include breasts becoming engorged, feeling full, warm, and sometimes leaking milk between feeds.
