As you experience the physical changes leading up to the birth of your baby, which ones are preparing your body to
breastfeed? And how does the process work?
Keep reading to learn about the amazing ways your body gears up to make breastfeeding possible.
Breast changes during pregnancy
You probably noted early in your
pregnancy—at around the fifth or sixth week—that your breasts became
fuller and your nipples more tender than before. Your nipples and the darker-colored area around them, called the areolae, may have enlarged and darkened. The small bumps on the areolae, called the Montgomery's glands, became more prominent.
Hormones that trigger milk production
Starting about the third month of pregnancy, more changes happen. A complex interplay of hormones—including prolactin, estrogen, progesterone and human growth hormone—leads to the growth of milk ducts and gland-producing cells in your breasts. This prepares your body to produce milk.
As your pregnancy progresses, the gland tissue needed to produce milk replaces much of the fatty and supportive tissue that normally makes up most of the breast. This causes your breasts to become substantially larger during pregnancy and lactation.
These changes may worry you that breastfeeding will cause your breasts to sag or change shape after
weaning. But there is no reason for concern. When you stop nursing, your milk glands are once again replaced by fatty and supportive tissue. With a return to pre-pregnancy weight, breasts go back to their approximate pre-pregnancy size and shape.
By the middle of your pregnancy, lactose, the sugar in milk, can be detected in your blood and urine. This indicates that milk production is beginning. At the end of the second trimester, your body has become fully capable of producing breastmilk—which means that even if your child is born prematurely, you will be able to produce it.
What is colostrum and when does it start?
Colostrum is the first milk produced. Rich in immunity-boosting proteins, colostrum is thick, somewhat sticky and yellow or orange in color. (If you notice yellow or orange stains on the inside of your
maternity bra, your breasts are making colostrum. However, some mothers do not notice any colostrum being secreted until after their babies are born.) At this time, you may notice more prominent veins on the surface of your breasts and that the areolae have enlarged and become darker.
When will my milk "come in?"
After your baby is born, the areolae of your breasts, and especially the nipples, will become extra sensitive to touch. When your baby's mouth touches the nipple, nerve cells will send a signal to your brain, causing the release of the hormone oxytocin. Oxytocin causes tiny muscle cells within the breasts to contract, squeezing milk from the milk-producing cells down the milk ducts toward small sacs or sinuses near the nipples.
As your baby suckles at the breast, drawing milk from the sinuses through the nipple and into their mouth, production of oxytocin will increase. This causes more milk to move through the ducts in a process called the
let-down or milk-ejection reflex. The actual production of milk is regulated by prolactin, another hormone, especially in the early weeks of lactation.
How the body maintains milk supply
As you continue to breastfeed, milk production becomes more dependent upon milk removal. This can happen either through nursing or expressing milk using your hands or a breast pump.
Through this complex system, your body ensures that when your infant is
hungry, your body can provide them with the nourishment they need.
More information