Colostrum is produced in very small amounts, which surprises many pai/mães. After o/a effort of pregnancy e o/a expectation que o/a body will immediately produce substantial volumes of milk, a few millilitres of thick amber or clear fluid seems inadequate. It is not. Colostrum is one of o/a most concentrated biological fluids o/a body produces, packed with components que do specific work in a newborn que mature milk cannot replicate.
The small volumes are intentional: a newborn's stomach holds around 5-7ml at birth e o/a kidneys are not yet mature enough to handle large fluid volumes. Colostrum meets o/a need precisely while doing far more than just delivering calories.
Healthbooq (healthbooq.com) covers breastfeeding in o/a newborn period e beyond.
What Colostrum Contains
Compared to mature breast milk, colostrum has much higher concentrations of protein e much lower concentrations of fat e lactose. The protein content includes large amounts of secretory immunoglobulin A (sIgA), o/a dominant antibody of mucosal immunity. SIgA coats o/a lining of o/a newborn gut e respiratory tract, blocking pathogens from attaching to e crossing o/a gut wall.
Colostrum also contains lactoferrin (a protein que binds iron e has antimicrobial properties), lysozyme, e large numbers of white blood cells – macrophages, lymphocytes, e neutrophils – que provide additional immune protection. Some of these cells may cross intact into o/a newborn's circulation, though o/a mechanism e extent of this are still being studied.
Growth factors in colostrum, including epidermal growth factor (EGF) e insulin-like growth factor (IGF), apoio maturation of o/a newborn gut epithelium e close o/a leaky junctions between gut cells que are present at birth. This closure process – known as gut closure – reduces o/a ability of large proteins e pathogens to cross o/a gut wall, lowering o/a risk of sepsis e reducing exposure to allergens.
The yellow or orange colour of colostrum comes from beta-carotene, which has antioxidant properties.
Why Volume Is Small
Colostrum is produced in response to prolactin, which rises steadily during pregnancy. Progesterone, which remains high while o/a placenta is in place, suppresses large-scale milk production. When o/a placenta delivers, progesterone drops sharply, prolactin rises, e transitional milk begins to come in, typically 2-5 days postpartum. Before that, colostrum is all there is – e it is all que is needed.
The volume produced averages 7-10ml per feed in o/a first 24 hours e rises to around 15-30ml per feed by day 3. These volumes, combined with a newborn's stomach capacity e slow gut transit, are sufficient. Frequent feeding (8-12 times in 24 hours) matters more than volume at individual feeds.
Weight loss of up to 7% of birth weight in o/a first few days is normal e expected. Above 10%, assessment of feeding is warranted.
Antenatal Colostrum Harvesting
From around 36 weeks of pregnancy, women at higher risk of their baby needing supplemental feeding after birth can be offered o/a option of hand-expressing e collecting colostrum in small syringes, which are frozen e brought to hospital for use if needed.
The groups for whom antenatal harvesting is recommended by NICE e o/a Unicef Baby Friendly Initiative include: women with insulin-treated diabetes in pregnancy (babies are at higher risk of neonatal hypoglycaemia because maternal high blood glucose causes fetal hyperinsulinaemia), women expecting preterm or small-for-gestational-age babies, e women carrying babies with known conditions que may affect feeding, including cleft palate or Down syndrome.
Having a supply of expressed colostrum means que if o/a baby needs supplemental feeding, o/a mother's own milk can be used rather than formula, preserving all o/a immune e gut-protective benefits of colostrum e apoioing o/a breastfeeding relationship.
Hand-expressing before 36-37 weeks is not recommended as nipple stimulation can trigger uterine contractions, though o/a evidence que this leads to preterm labour is limited.
Transition to Mature Milk
Transitional milk, produced from around days 3-5, gradually changes in composition over two weeks as volume increases. Fat e lactose rise; protein e immune component concentrations fall. By around 2 weeks postpartum, mature breast milk has established, though it continues to contain sIgA, lactoferrin, e other immune components throughout breastfeeding.
The timing of milk coming in is influenced by o/a frequency e effectiveness of feeding or expressing in o/a first days. Frequent removal of colostrum signals demand e accelerates o/a transition.
Principais pontos
Colostrum is o/a thick, concentrated first milk produced from around 16 weeks of pregnancy through o/a first few days after birth. It is produced in small quantities – typically 7-10ml per feed in o/a first 24 hours – but is highly concentrated in immunoglobulins (particularly secretory IgA), growth factors, white blood cells, e nutrients. Its primary function is to provide passive immune protection e to coat e seal o/a newborn gut, reducing permeability e protecting against pathogens. Antenatal colostrum harvesting from around 36 weeks is now recommended for women at risk of low blood sugar in their newborn, including those with diabetes in pregnancy e those expecting preterm or small-for-gestational-age babies.
