How and When Does Breast Milk Form?
Dear mothers, contrary to what many people think, milk production does not start immediately after birth.
In fact, the first stages of breast milk production begin in the second trimester of pregnancy. During this period, breasts begin to produce colostrum (colostrum), which is the baby's first and most valuable food. For this reason, even if premature birth occurs, the body is prepared for milk production.
However, the progesterone hormone, which is at high levels in the body during pregnancy, prevents the intense secretion of milk. After birth, progesterone and estrogen levels drop rapidly as the placenta separates. This hormonal change triggers the process that enables milk production to begin actively.
When Does Milk Come After Birth?
A significant increase in milk production begins within the first 30–40 hours after birth. Although the colostrum that arrives in the first days may seem small in quantity, it is a very dense, immune-supporting and nutritious milk.
Therefore, in the first days when breast milk is not yet fully produced, the baby often does not need additional food. Colostrum is designed to meet the essential nutrients the baby needs.
Usually within 2–3 days after birth, mothers begin to experience a feeling of fullness in their breasts and a significant increase in the amount of milk is observed.
How to Control Milk Production in the First Days?
Breast milk production is not a process that starts only with the baby sucking in the first days after birth.
Milk production in the last stages of pregnancy and the first days after birth is largely governed by hormones. This system is called endocrine control system.
This process consists of two basic phases:
Lactogenesis I
This is the period that begins in the second half of pregnancy and when colostrum production occurs.
Lactogenesis II
This is the period that begins approximately 30–40 hours after birth and sees a significant increase in milk volume.
Therefore, the mother's desire to breastfeed, her psychological state, rest and feeling of well-being play an important role in the healthy progress of the breastfeeding process.
Why Can Milk Drop Be Delayed?
In some mothers, milk letdown may occur later than expected due to physiological reasons. Especially cesarean birth, intense postpartum stress, some hormonal conditions or the mother's health condition may affect the onset of milk production.
Therefore, the fact that the amount of milk seems low in the first days does not always mean that insufficient milk is produced. When experiencing concerns about breast milk, it may be helpful to seek support from a lactation consultant or healthcare professional before starting formula.
Result
Breast milk production actually begins long before birth, in the second trimester of pregnancy. With the hormonal changes that occur after birth, the amount of milk increases and milk production usually becomes evident within the first few days. Colostrum, which arrives in the first days, is an extremely valuable food that meets the baby's needs. Therefore, before worrying about the amount of milk, it is important to understand the natural physiology of the process and get expert support when necessary.
Dietitian Yasemin Tangören Öztürk
June 23, 2026
