Milk Production

Milk let-down reflex

The hormones produced during your pregnancy help prepare your breasts for the production of milk. Once your baby is born and put to the breast to suck, a hormone called oxytocin is released from the pituitary gland at the base of your brain, which sends a ‘let-down’ signal to the breast. The muscles supporting the milk glands contract and the milk is pushed down the 15 or 20 milk ducts as the baby sucks. Many women feel a slight tingling in their breasts, and their womb contracting when their milk lets down. These feelings normally disappear within a week or two. You may also experience a let-down when you hear your baby cry, or if you think about him when you are apart. If you get tense or are very stressed, oxytocin is not released, making it difficult for your milk to let down. Therefore, it is essential for successful breast-feeding that you feel calm and relaxed. This can be helped by preparing everything needed for a feed in advance. Make sure you are sitting comfortably with your back straight, and that the baby is well-supported. Take time to position him on to the breast correctly. Pain caused by incorrect positioning also affects oxytocin being released, which in turn affects the let-down reflex.

Milk composition

The first milk your breasts will produce is called colostrum. It is higher in protein and vitamins and lower in carbohydrate and fat than the mature milk that comes in between the third and fifth day. Colostrum also contains some of your antibodies, which will help your baby resist any infections you have had. Compared to the mature milk that soon follows, colostrum is much thicker and looks more yellow. By the second to third day, the breasts are producing a mixture of colostrum and mature milk. Then, somewhere between the third and fifth day, the breasts become engorged, and they will feel very hard, tender and often painful to the touch. This is a sign that the mature milk is fully in. The pain is caused not only by the milk coming in, but also by the enlargement of the milk glands in the breasts and the increased blood supply to the breasts. When the milk comes in, it is essential to feed your baby little and often. Not only will it help stimulate a good milk supply, but it will also help relieve the pain of engorgement. During this time it may be difficult for your baby to latch on to the breast and it may be necessary to express a little milk before feeding. This can be done by placing warm, wet flannels on the breasts and gently expressing a little milk by hand. Many mothers also find some relief by placing the leaves of a chilled cabbage inside their bras between feeds.

Mature milk looks very different from colostrum. It is thinner and looks slightly blue in colour, and its composition also changes during the feed. At the beginning of the feed, your baby gets the fore milk, which is high in volume and low in fat. As the feed progresses, your baby’s sucking will slow down and he will pause for longer between sucks. This is a sign that he is reaching the hind milk. Although he only gets a small amount of hind milk, it is very important that he is left on the breast long enough to reach it. It is this hind milk that will help your baby go longer between feeds. If you transfer him to the second breast before he has totally emptied the first breast, he will be more likely to get two lots of fore milk. This will have a knock-on effect and leave him feeling hungry again in a couple of hours. Another feed of fore milk will quickly lead to your baby becoming very ‘colicky’. While some babies do not get enough from only one breast and need to be put on the second breast, always check that he has completely emptied the first breast before transferring him (see here). I find that at the end of the first week, by making sure babies are given around 25 minutes on the first breast, and offered the second breast for 5–15 minutes, I can be sure that they are getting the right balance of fore milk and hind milk. It also ensures that they are content to go between 3–4 hours before demanding their next feed. If your baby is feeding from both breasts at each feed, always remember to start the next feed on the breast you last fed from, so that you can be certain each breast is totally emptied every second feed.

In order to encourage a quick and easy let-down, and to ensure that your baby gets the right balance of fore milk and hind milk, the following guidelines should help:

• Make sure that you rest as much as possible between feeds, and that you do not go too long between meals. Also, eat small, healthy snacks between meals.
• Prepare in advance everything needed for the feed: a comfortable chair with arms and a straight back, and perhaps a footstool. Cushions to support both you and the baby, a drink of water and some soothing music will all help towards a relaxing, enjoyable feed for both of you.
• It is essential that you take your time to position the baby on the breast correctly; poor positioning leads to painful and often cracked, bleeding nipples. This, in turn, can affect your let-down and result in a poor feed.
• Once the milk is in and you have built up the time your baby feeds from the breast, it is important that he is on the breast long enough to reach the hind milk. Some babies need up to 30 minutes to empty the breast. By gently squeezing your nipple between your thumb and forefinger, you will be able to check if there is any milk still in the breast.
• Never, ever allow your baby to suck on an empty breast; this will only lead to very painful nipples.
• If you find your baby is taking a lot less time than 30 minutes to feed, is happy and content until his feed and is gaining weight well, then you clearly have a very efficient feeder and there is no need to concern yourself if you finishes his feed much sooner than I suggest.
• Not all babies need the second breast in the early days. If your baby has totally emptied the first breast, burp him and change his nappy, then offer him the second breast. If he needs more he will take it. If not, start him off on that breast at the next feed.
• If your baby does feed from the second breast, you should still start on that breast at the next feed.