Breast Milk Production

As you and your baby work to master breastfeeding, it helps to know a little bit about the mechanics of how it all works:

Anatomy

Most women find that their nipples and areolae – the area of dark skin around the nipple – get a bit larger and darker during pregnancy. Some experts suggest that the body is working to create an easier target for the baby to latch onto. The areolae also feature small bumps call Montgomery glands, which produce a natural antibacterial oil to clean, lubricate and protect the nipple during breastfeeding. Each nipple has about 15 to 20 apertures through which the milk can flow. A nursing infant moves her jaw and presses down with her tongue to create suction and cause the milk to flow out of the breast and into her mouth.

Your body’s response

When your baby sucks on your breast, she stimulates the nerve endings in the nipple and areola, and this cues your pituitary gland to release the hormones prolactin and oxytocin. Prolaction prompts your body to turn nutrients from your blood supply like proteins and sugars into breast milk. Oxytocin prompts your body to pass the milk through your milk ducts and out of your body in what is called a “let-down” response. During letdown – as your infant begins to actively suck and swallow the breast milk – you may find that milk drips from the opposite breast as well (breast or nursing pads can be handy in these moments, especially during the first few weeks). You may also feel a tingling or swelling sensation in your breast, and you may experience a cramping of the uterus (nursing hormones like oxytocin prompt it to contract and regain its pre-pregnancy size after you’ve given birth). Many women also feel extremely thirsty during letdown, so it’s always a good idea to have a glass of water next to you when nursing. Sometimes let-down happens even when you are not nursing your child – if, say, you think fond thoughts of her or if you’re a little late for a feeding (another reason to use cotton breast pads, especially during early weeks of breastfeeding). Also, let-down happens best when you’re well-rested and relaxed, so do your best to nurse your baby in a stress-free atmosphere, whenever possible.

Breast milk

• Colostrum: When you first begin breastfeeding – for the first two or three days – your baby takes in early milk called colostrum, which is designed to meet her earliest needs. Thick and yellow, colostrum is high in protein and low in fat and sugar. The protein content, which is three times higher than it is in mature milk, contains essential antibodies that are passed from you to your baby. It protects your baby and has a natural laxative effect that helps your baby process and pass her first stool, an odorless, sterile tarlike substance called meconium. Though your baby doesn’t take in much colostrum, it’s still important to nurse her frequently during the early days so that she gets the nutrients she needs and signals your body to create more milk as she matures.
• Mature milk: Two to three days after your child begins nursing, your body will change and increase the quantity of milk production, especially if you have begun breastfeeding your baby right away and are feeding her frequently in these early days. At the beginning of each feeding, your baby will take in foremilk, which is thin and watery and may have a light-blue tint to it. The water content in foremilk is high to quench your baby’s thirst. After your baby has been nursing at the breast for several minutes, your body will release the hind-milk, which is creamier in texture and higher in fat content. The hind-milk will help your baby feel satisfied and relaxed and full. Eventually, your baby will zone out with satisfaction and come off the breast on her own. She may even fall asleep.