What is colostrum, and when does milk come in?
Colostrum is the first milk produced after birth. Breasts may feel fuller around two to four days later, though this is a broad guide.
The short answer
Colostrum is the first milk produced after birth, usually thick and golden yellow in small amounts. NHS guidance says breasts may feel fuller around two to four days after birth. Treat that as a broad guide, not a precise deadline.
What colostrum is
Colostrum is the first milk your breasts make after birth. NHS guidance describes it as usually thick and golden yellow and produced in small amounts. Your care team can help check how feeding is going rather than comparing amounts with someone else’s.
Newborns often feed frequently in the early days. Follow any feeding plan from your midwife, health visitor or doctor and ask them if you’re unsure how it applies to your baby.
When milk volume changes
The NHS says you may notice your breasts becoming fuller around two to four days after birth. This is often called milk coming in. The timing is a broad guide rather than an exact deadline. Your baby may continue to feed often in the early days, then have fewer, longer feeds after a few days.
If your care team has given you a feeding plan, follow it. Speak to your midwife or health visitor if you’re worried about breastfeeding or think your baby isn’t getting enough milk.
When to ask for support
A midwife, health visitor or breastfeeding supporter can help with positioning and attachment and talk through your questions. For a separate overview of feeding frequency, read how often a newborn may feed.
This article summarizes NHS guidance from the United Kingdom. Services differ by location. BabyDays can record feeds, but it can’t measure milk transfer or check your baby’s health. Ask your local care team if you’re worried.
Sources and further reading
Sources checked 12 October 2026. This page doesn’t replace advice from your own doctor.