Girls don't typically start producing milk until they are pregnant. Milk production, or lactation, is a biological process triggered by hormonal changes associated with pregnancy and childbirth.
The Role of Hormones in Milk Production
Lactation is a complex process regulated by hormones. During pregnancy, the body starts producing hormones like prolactin and estrogen, which prepare the breasts for milk production. This preparation usually begins around the midpoint of pregnancy, between weeks 16 and 22. At this stage, the breasts begin producing colostrum, a yellowish, nutrient-rich fluid that serves as the baby's first food.
Following childbirth, hormonal changes and the act of breastfeeding further stimulate milk production. The process of milk production is driven by the body's response to the demands of breastfeeding.
When Milk Production Begins
- During Pregnancy: Colostrum production starts between weeks 16 and 22 of pregnancy. This is a precursor to mature breast milk.
- After Childbirth: Mature milk production begins after delivery, triggered by hormonal shifts and the baby's sucking.
It's important to note that milk production outside of pregnancy (galactorrhea) can sometimes occur due to hormonal imbalances or medication side effects. This is not the typical onset of milk production associated with puberty or age.
Additional Considerations
While some sources mention changes in breast development starting around age 35, this refers to age-related changes and not milk production. Puberty brings about breast development, but it does not initiate milk production unless pregnancy occurs.
