Your breastfeeding journey begins in pregnancy. One of the earliest signs of a first pregnancy is the formation of Montgomery’s Tubercles, little glands on the areola, which you might notice as small bumps on the dark area around the nipple. They may even appear before your period is late! These release an oil that keeps the nipple moist and lubricated during breastfeeding and which has antibacterial properties to prevent infection. When washing, it is important not to use any harsh soaps which may disrupt the function of this oil which increases the risk of cracking of the skin of the nipple and therefore infections. As you continue through your pregnancy, you may notice an increase in breast size due to formation of milk producing tissue, and some mild tenderness also. You may also notice some darkening of the areola and also more prominence of the veins in your breasts as blood supply to the breasts increase.
In the second half of your pregnancy, your breasts begin to produce colostrum, the first milk which is rich in nutrients and anti infective agents. This is called Lactogenesis I and is controlled by the hormone prolactin. High levels of the hormone progesterone which is present in pregnancy, blocks the production of larger amounts of mature milk until your baby is born. The next phase of milk production is called Lactogenesis II and happens after your baby is born. There is a sudden drop in the levels of the hormones oestrogen and progesterone, which allows high levels of prolactin to trigger copius milk production, or your ‘milk coming in’. Biochemically this happens somewhere between 30 and 40 hours after birth but most mothers feel their milk come in around 2 or 3 days after birth.
The first two phases of milk production- colostrum production in pregnancy and milk coming in after delivery are controlled by changes in hormones triggered in normal pregnancy and birth. This means that they should happen automatically during pregnancy and after birth, so there is no need to worry about it. A common breastfeeding myth is that it is more difficult for mothers who give birth by C section to breastfeed as it is thought that the hormones of labour or delivery of the infant are what triggers milk coming in. What actually triggers Lactogenesis II or milk coming in is the separation of the placenta from the wall of the uterus, which happens in all deliveries whether vaginal or C section, so all mothers can expect to produce colostrum and milk during pregnancy and after delivery, no matter how they give birth
The next phase of milk production is controlled locally, at the breast. This phase, Lactogenesis III, is a supply and demand system as your breasts respond to your baby’s appetite. The more often the breast is stimulated by suckling, the more milk will be produced. When your baby feeds, stimulation at the nipple causes a release of the hormone oxytocin, which triggers the milk ejection reflex, which you will feel as ‘let down’. The other hormone involved is prolactin. If you bring your baby to your breast to feed regularly, your body will produce enough milk for her according to her appetite. On demand feeding, especially in the early days and weeks of breastfeeding, will help your body to build the supply of milk your baby needs. Babies have very small stomachs, particularly when they are newborn and it is normal for them to need to be fed frequently. This does not mean that you are not producing enough milk, it just means your baby is communicating with your body about how much milk she needs. Once your milk supply is established, it continues on a supply and demand system, so for the duration of your breastfeeding journey, you will continue to produce milk for as long as your child feeds.
Your milk is tailored to your baby’s unique needs- to learn more about breastmilk composition see our articles on breastmilk composition and for more detailed information on breastmilk production see our article on breastmilk production physiology.