Colostrum

Colostrum is a special type of breast milk that is produced during pregnancy and is expressed for the first few days after giving birth. It is sometimes called beestings or first milk. Not only can it look quite different to mature breast milk, but it also has a different nutritional content to the mature breast milk that is produced around four days after birth.

Why colostrum is special

Colostrum contains highly concentrated levels of essential nutrition that your baby needs at the start of life. It is very easy to digest and contains enzymes that help your baby to fully absorb its nutrients. It contains higher concentrations of proteins and minerals and lower concentrations of fat than mature breast milk, but these concentrations are reversed as your baby develops and mature breast milk is produced.

Colostrum contains antibodies that help your baby to recognise and fight diseases. During pregnancy your baby received some antibodies from you in the form of immunoglobulin B (IgB) but colostrum contains another type of antibody known as immunoglobulin A (or IgA). IgA is an essential part of what are called 'mucosal secretions'; these include saliva and tears and these secretions are found in the lungs, gastrointestinal tract and other parts of the body. These mucosal secretions help to protect the body from the bacteria and viruses that multiply in these secretions. Colostrum also contains immunoglobulin G and immunoglobulin M (IgG and IgM) as well as many other important molecules that are required by the immune system. It also helps the bacteria lactobacillus bifidus to colonise your baby's gut which also helps to prevent infection.

The yellowish colour of colostrum comes from the high levels of vitamin A or beta-carotene that it contains (which is the same substance that makes carrots orange). Vitamin A has many jobs in the body with its main ones being assisting with sight and working as an antioxidant. Antioxidants help to protect cells from damage. Colostrum also contains vitamin C, also known as ascorbic acid. This vitamin helps to protect and keep cells healthy. Babies need a good supply of vitamin C for growth and development. Vitamin E is another antioxidant contained in colostrum which helps to keep cells healthy.

There are also a variety of minerals found in colostrum including calcium, phosphorous, iron and zinc. Calcium not only helps to grow and strengthen bones and teeth but it is also involved in muscle contractions. Phosphorous helps to strengthen bones and teeth as well as helping to release energy from foods. Iron is required for making red blood cells which are essential for moving oxygen around the body. Zinc helps the body to process food, plays an important role in making cells and enzymes as well as helping wounds to heal. Deficiencies of these key minerals in childhood can cause disorders such as rickets or scurvy.

Colostrum also contains a variety of molecules called growth factors, these all have specific names, but perhaps one of the most common growth factors is IGF-1 or insulin-like growth factor 1, which is essential for development. Many of these growth factors act as signals which control production of specific proteins. It is these proteins that are essential to help the gut grow and develop in the new-born.

It also acts as a laxative, helping your baby to pass its first stool, which is called meconium. This process is very important as it removes the build-up of bilirubin from your baby's body. Bilirubin is produced when red blood cells are broken down through a normal process at the time of birth and it is the excess amounts of bilirubin that cause jaundice in babies. The liver is unable to break down the bilirubin and remove it from the body fast enough.

How much colostrum does my baby need?

You may be worried that the quantity of colostrum that is produced is not enough for your baby. At one day old, your baby's stomach is about the size of a marble and can only hold between 5 and 7 ml (around a teaspoon) of milk.

It is recommended that you try and breastfeed between eight and twelve times in every twenty four hours as this ensures that your baby has the maximum amount of colostrum in its first few days.

How long will I produce colostrum for?

If you have started breastfeeding early and have continued to breastfeed frequently then mature milk will start to be produced around the fourth day after birth. The colour will become lighter and the volume will then increase. Mature breast milk will continue to provide appropriate nutrition to your baby as it develops.

What if I am unable to breastfeed?

You may be unable to breastfeed for a number of reasons, including illness or because of medications, or you may prefer to bottle feed. If you are expressing milk for bottle feeding, then do make sure that you are storing the milk properly; your midwife or health visitor can provide further guidance.

If you are bottle feeding with formula, it will not contain the same level of antibodies as breast milk, although whey-dominant milks are the most similar to breast milk for other nutritional values.

However you feed your baby this is a critical part of their first few days of life and so you must take the time to discuss feeding with your partner, midwife and other new mums both during your pregnancy and after birth.