Colostrum: The first breastmilk - Evidence Based Babies
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Colostrum: The first breastmilk

Let’s talk about colostrum

What is colostrum?

Colostrum is breastmilk.

Colostrum is the first form of breastmilk that your breasts will produce. It’s usually thick and sticky in consistency and yellow in color, but it can differ from person to person and even from day to day.

The breasts will start producing colostrum around 16 weeks of pregnancy and it will continue to produce colostrum for the first few days after birth, usually until about day 2-4 after which your breastmilk will become copious and start transitioning to mature breastmilk.

Colostrum has not only been called liquid gold due to the amazing composition, but also due to the amazing protection it offers. Some call it natures first vaccine, due to it being full of protection for newborn babies. The main reason for colostrum is firstly a protective one, to give baby a boost in all protection for the first few weeks. It’s second reason is a nutritional one, and yes, it’s full of all the needed nutrition to meet all of your baby’s needs.

Protective value

– Living Leukocyte cells

Colostrum contains about 146 000 Leukocyte cells per ml. The function of living cells is to create antibodies to help protect babies against pathogens.

– Lactoferrin

– Lactoferrin is responsible for iron transport and binding. It helps protect a newborn against infection by keeping the iron away from the pathogens so it can’t bind with the iron. Pathogens need iron for survival.

– Secretory IGA

– Secretory IGA, also known as SIGA is the main immunoglobulin found in breastmilk. Immunoglobulins are better known as antibodies. Secretory IGA is 15-40 times higher in the first 24 hours. It helps seal an infant’s gut to better protect them against infections.

– Helps establish a newborn’s microbiome

The good bacterium in breastmilk helps the infant’s gut to establish beneficial, non-pathogenic bacteria, particularly bifidus flora.

– Vitamin A

The reason for colostrum’s yellow color is because of the high levels of beta-carotene. The high levels of vitamin A offers even further immune protection.

– Sugars (HMO’S)

Functions as a prebiotic, decoy receptors for pathogens and it aids in sialic acid which is vital for brain development and function.

– Protein

There are two types of protein, whey and casein. Whey is much easier to digest than casein, therefore colostrum has a whey to casein ratio of 90:10 in comparison to the 60:40 in mature milk. The high ratio of whey is the reason why breastmilk digests so quickly and also why it has a laxative effect on newborns.

– Growth factors

Colostrum contains high amounts of growth factors including Epidermal growth factor, TGF-B and Colony stimulating factor which promotes gut closure.

Nutritional value

– Water

– Carbohydrates

– Protein

– Fat

– Vitamins and minerals

Colostrum contains all the needed protective and nutritional value that a newborn need. Even though it’s small in quantity, it’s extremely high in quality.

Common myths

– No leakage equals no milk

Some mothers may wonder if no leaking from the breast during pregnancy means they won’t have any milk once the baby is born. I’m here to assure you that leaking colostrum or even mature milk in the postpartum period is absolutely no indication of whether you have breastmilk. Some mothers may leak, and some may never leak, both are completely normal.

– Colostrum isn’t milk

A lot of people tend to believe that colostrum isn’t milk, and their “real” white milk only “comes in” after a few days. This is actually false, colostrum is milk. It’s the very first type of milk your breasts will produce and it’s extremely important for your baby.

– Colostrum isn’t enough for a baby

This is completely false. The body produces very small amounts of colostrum in the first few days for a reason. Because that’s all your baby needs. They have very small stomach capacity in the first few days. Babies do not need bottles of milk to fill them up, they only need a tiny bit of milk, frequently. This is why it’s so important to feed frequently, this will keep your baby’s stomach filled.

– I don’t have any colostrum because I can’t squeeze it out of my nipples, or I don’t get anything out when I pump

Breasts need stimulation for oxytocin to release to trigger a letdown for the colostrum to start flowing. So, it takes some stimulation before just being able to get some colostrum out. It should also be noted that you shouldn’t squeeze your nipples, as this may cause damage, the correct hand express techniques should be used to successfully extract colostrum by hand. We also have to remember that colostrum is a very thick and sticky substance, so a pump won’t be able to get colostrum out like you would by hand. Always remember, your baby is much more efficient than anything else in removing colostrum from the breast.

– You need medication to “bring your milk in”

We have to remember that milk doesn’t “come in”, as colostrum is milk. It only changes in quantity and it changes from colostrum to transitional milk and then mature milk. Lactogenesis 2, the onset of copious milk “white milk”, is triggered by the birth of the placenta, so it’s completely hormonal. Your milk will increase and mature on its own between day 2-4 on average.

Some factor may cause a delay in Lactogenesis 2:

– Not breastfeeding frequently enough

– First birth

– Caesarean section births

– Pain medications during labor

– Large amounts of IV fluids during labor

– Obesity

– Diabetics

– A prolonged second stage of labor

– Stressful labor or delivery

– Postpartum edema

– Retained placenta

– Contraindicated herbs or medicine

– Hormonal health complications including, diabetes, PCOS, infertility issues, hypothyroidism, insulin resistance and diabetes.

If you know you fall into one of these risk factors, it may be a good idea to consult an International Board Certified Lactation Consultant (IBCLC) to assess and monitor you and your newborn to ensure the best start possible.


– Colostrum is milk

– It provides protection to a newborn

– Highly nutritional

– Colostrum is everything your newborn needs

Additional information and resources:

A study of the factors affecting time to onset of lactogenesis-II after parturition

Human Milk Composition: Nutrients and Bioactive Factors


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