Quick Answer
Colostrum is the first milk produced by the breast, present from around mid-pregnancy and available to the baby from the first feed after birth. It is thick, concentrated, and typically yellow or golden in colour. The volumes are small by design: a newborn's stomach holds approximately 5 to 7 ml at birth, and colostrum is produced in volumes that match this capacity closely. The most common concern new parents have is that small colostrum volumes mean the baby is not getting enough, but this reflects a mismatch between what parents expect and what the newborn actually needs. A baby who is feeding frequently, producing the expected number of wet and dirty nappies, and losing no more than the normal amount of birth weight is getting enough, even if the mother cannot see or measure what the baby is taking.
What Colostrum Is
Colostrum is not a watered-down precursor to real milk: it is a distinct biological fluid with a composition precisely suited to the newborn's needs in the first days of life. Its key characteristics include:
- High concentration of immunoglobulins, particularly secretory IgA. These coat the lining of the newborn's gut and provide early immune protection, blocking pathogens from crossing the gut wall before the baby's own immune system is functional. The gut of a newborn is permeable in the first days of life (sometimes called open gut), and colostrum's IgA is the primary protection during this window
- Growth factors and cytokines. Colostrum contains epidermal growth factor and other signals that promote the maturation and closure of the newborn gut lining, reducing permeability and the risk of allergen and pathogen entry
- High protein, low fat, low sugar. The macronutrient profile of colostrum is very different from mature milk: it is higher in protein and lower in fat and lactose, which suits the newborn's limited digestive capacity and the need for concentrated nutrition in small volumes
- Natural laxative effect. Colostrum stimulates the passage of meconium (the newborn's first black, tarry stools), which clears bilirubin from the body and reduces the risk of neonatal jaundice
- Electrolyte balance suited to the newborn. Higher sodium and lower potassium than mature milk, matching the newborn's fluid and electrolyte needs in the immediate postpartum period
How Much Colostrum Is Normal
Total colostrum output in the first 24 hours is typically between 20 and 80 ml across all feeds combined. Individual feeds may produce only 5 to 15 ml, which is invisible in a nappy and feels like nothing to a parent who cannot see it transfer. These volumes increase over the first two to three days as feeding frequency stimulates supply and as lactogenesis II (the milk coming in) begins around day 2 to 5.
Colostrum is not easily expressed in large quantities by hand or pump in the first days, which leads many mothers to assume they have no milk or very little. The breast is producing what it produces, and the baby's direct suckling at the breast is typically more effective at extracting it than a pump or hand expression in these early days.
Signs the Baby Is Getting Enough Colostrum
Because colostrum volumes cannot be directly measured at the breast, adequacy is assessed through the baby's outputs and behaviour:
- Wet nappies following the day-by-day pattern. Day 1: at least one wet nappy. Day 2: at least two. Day 3: at least three. From day 4 to 5 onward, when mature milk has arrived: at least six per 24 hours. Urine should be pale yellow by day 4; dark yellow or orange urine (urate crystals, sometimes called brick dust) on day 3 or 4 warrants a conversation with a midwife or lactation consultant about intake
- Dirty nappies transitioning from meconium. The first stools (meconium) are black and tarry. By day 2 to 3, stools should begin transitioning to greenish-brown as colostrum clears the meconium, and by day 4 to 5 they should be transitioning to the yellow, seedy stools of a breastfed baby receiving mature milk. Continued black stools beyond day 4 may indicate inadequate intake
- Weight loss within the normal range. Some weight loss in the first days is expected as the baby loses fluid and passes meconium. A loss of up to 7 percent of birth weight is considered normal; 10 percent is the threshold at which more careful monitoring and lactation support is typically recommended. Weight should begin to recover by day 4 to 5 and return to birth weight by around day 10 to 14
- Feeding eight to twelve times per 24 hours. Frequent feeding in the first days is both a sign of adequate hunger signalling and the mechanism by which supply is stimulated. A baby who is too sleepy to feed eight times per 24 hours in the first days may need to be roused for feeds
- Audible swallowing during feeds. A baby who is transferring milk will make audible swallowing sounds (a soft, low-pitched gulping sound distinct from the faster sucking movements before milk is flowing). The absence of audible swallowing after the initial fast suck is a reason to seek a latch assessment
When to Seek Support
- The baby is losing more than 10 percent of birth weight
- Wet nappies are fewer than expected for the baby's day of life
- Urine is dark yellow or orange after day 3
- Stools remain black or dark green beyond day 4
- The baby is very sleepy and difficult to rouse for feeds
- Feeds are painful or the latch is not established, as this affects milk transfer regardless of supply
- The mother has concerns: midwife and lactation consultant support in the first days is exactly what it is for
Key Takeaway
Colostrum is a biologically distinct and highly functional first milk, not a placeholder until real milk arrives. Its small volume is intentional and matched to the newborn's stomach capacity. Adequacy is assessed through outputs (nappy pattern and weight loss within normal range) and feeding behaviour (eight to twelve feeds per 24 hours, audible swallowing), not through what the mother can express or see. The day-by-day nappy pattern is the most practical daily check for new parents. If any output signs fall outside the expected range, or if feeding is painful or not establishing, midwife or lactation consultant support in the first days is both appropriate and available.
Parents Also Ask
When Does Breast Milk Come In After Birth?
How Do I Know If My Baby Is Getting Enough Milk?
What Is Power Pumping and Does It Increase Milk Supply?
This article is for informational purposes only and is not a substitute for professional medical or lactation advice. If you have any concerns about your baby's intake or weight in the first days, contact your midwife, health visitor, or a lactation consultant promptly.