Milk typically comes in after the colostrum phase around 2 to 5 days after the baby is born. Colostrum, the thick, nutrient-rich early milk, is produced from about mid-pregnancy and lasts up to about 3 to 5 days after birth. After this period, milk production increases, and the milk transitions to what is called transitional milk, which gradually changes to mature milk over the next 10 to 15 days. The "milk coming in" is often marked by signs like breast fullness, swelling, warmth, and a change in milk appearance from thick yellow colostrum to thinner, whiter milk. This increase in milk volume is hormonally controlled and can happen gradually.
Summary of timing:
- Colostrum produced and given in first 3-5 days after birth.
- Transitional milk phase starts around 2-5 days postpartum.
- Mature milk generally established by 10-15 days postpartum.
Signs milk is coming in include breast fullness and changes in baby feeding patterns, but the process varies among mothers.
