Key takeaways: Colostrum is the thick, yellowish first milk your body makes. It comes in small amounts that match a newborn’s tiny stomach. It’s rich in antibodies, protein, and growth factors. Frequent feeding in the first days helps your milk increase between days 2 and 5.
Many new parents worry that they “don’t have any milk yet.” In fact, you’ve been making milk since mid-pregnancy. That first milk, called colostrum, is exactly what your newborn needs.
What Is Colostrum?
Colostrum is the first stage of breast milk. It’s often thick and yellow or orange, though it can also be clear or white. Your body begins making it around the middle of pregnancy, and it’s what your baby gets in the first 2 to 5 days after birth.
Why It’s So Important
- Immune protection: colostrum is especially rich in secretory IgA, an antibody that coats your baby’s gut and helps protect against germs. It also contains white blood cells, lactoferrin, and other protective factors.
- Gut development: growth factors in colostrum help mature your baby’s intestinal lining.
- Gentle laxative: colostrum helps your baby pass meconium, which also helps clear bilirubin and reduce jaundice.
- Protein and nutrients: it’s higher in protein and some vitamins and minerals than later milk.
- Blood sugar support: frequent colostrum feeds help keep a newborn’s blood sugar stable.
How Much Does My Baby Need?
Very little. On the first day, a newborn’s stomach comfortably holds only about a teaspoon (5 to 7 mL) per feed. Studies of breastfed newborns find average intakes of roughly 15 to 30 mL (half an ounce to an ounce) total on the first day, rising quickly over the next several days. Small amounts, given often, are perfect.
From the author
From First Breath to First Birthday is my month-by-month guide to your baby’s first year, written as a NICU and postpartum nurse. If you want feeding help you can flip to in the middle of the night, my book walks you through feeding month by month, from the very first latch to the first birthday.
When Does Mature Milk Come In?
Between about days 2 and 5, hormone changes after the placenta is delivered trigger a big increase in milk production. You may notice fuller, heavier breasts. Milk gradually changes from colostrum to “transitional” milk and then to mature milk over the first couple of weeks.
Milk may come in later for some parents, including those who had a cesarean birth, a long or difficult labor, significant blood loss, diabetes, obesity, or a first baby. Frequent feeding, skin-to-skin, and early hand expression help.
Helping Your Baby Get Colostrum
- Skin-to-skin right after birth and often in the first days.
- Feed early, ideally within the first hour.
- Feed often, 8 to 12 or more times in 24 hours.
- Hand expression: if your baby is sleepy, premature, or separated from you, hand express colostrum into a spoon or small cup. Hand expression is often more effective than a pump for colostrum because the volume is so small.
Collecting Colostrum Before Birth (Antenatal Expression)
Some parents hand express and store colostrum in the last weeks of pregnancy, especially if their baby may be at risk for low blood sugar (for example, with diabetes in pregnancy). A large Australian trial found that antenatal expression from 36 weeks in low-risk pregnancies with diabetes was safe and didn’t increase NICU admissions. Talk with your obstetric provider before starting, since it’s not right for everyone, and ask how to store and bring it to the hospital.
What If My Baby Needs More?
Sometimes a baby needs more than colostrum alone provides: for example, with significant weight loss, low blood sugar, or dehydration. Your care team can help with supplementation, using your expressed colostrum first, then pasteurized donor milk or formula if needed, while protecting your supply.
Call your baby’s doctor if your baby: isn’t waking for at least 8 feeds a day, has fewer wet or dirty diapers than expected, is very sleepy or floppy, looks increasingly yellow, or hasn’t passed meconium by 48 hours.
The Bottom Line
Colostrum is small in volume and huge in value. Frequent feeding and skin-to-skin in the first days give your baby this protective first milk and help your mature milk come in.
For more newborn and breastfeeding resources, see my book, From First Breath to First Birthday.
Related Articles
- Delayed Milk Coming In: Risk Factors and What Helps
- Pumping for a Baby in the NICU
- Your Newborn’s First 24 Hours: What Happens in the Hospital, Hour by Hour
Sources
- Meek JY, Noble L; Section on Breastfeeding. Policy statement: breastfeeding and the use of human milk. Pediatrics. 2022;150(1):e2022057988.
- Ballard O, Morrow AL. Human milk composition: nutrients and bioactive factors. Pediatr Clin North Am. 2013;60(1):49-74.
- Santoro W Jr, Martinez FE, Ricco RG, Jorge SM. Colostrum ingested during the first day of life by exclusively breastfed healthy newborn infants. J Pediatr. 2010;156(1):29-32.
- Forster DA, Moorhead AM, Jacobs SE, et al. Advising women with diabetes in pregnancy to express breastmilk in late pregnancy (Diabetes and Antenatal Milk Expressing [DAME]): a multicentre, unblinded, randomised controlled trial. Lancet. 2017;389(10085):2204-2213.
- Nommsen-Rivers LA, Chantry CJ, Peerson JM, Cohen RJ, Dewey KG. Delayed onset of lactogenesis among first-time mothers is related to maternal obesity and factors associated with ineffective breastfeeding. Am J Clin Nutr. 2010;92(3):574-584.
- Kellams A, Harrel C, Omage S, Gregory C, Rosen-Carole C; Academy of Breastfeeding Medicine. ABM Clinical Protocol #3: Supplementary feedings in the healthy term breastfed neonate, revised 2017. Breastfeed Med. 2017;12(4):188-198.
This article is for general education and is not a substitute for individualized medical advice. Always talk with your baby’s health care provider or your own provider about your specific situation. If you think your baby or you may have a medical emergency, call 911.
