It should be self-evident that very small people will have very small stomachs however many adults are surprised when they learn about the limited capacity of a newborn’s stomach.
Here are some facts that may help you (or those around you) better visualize what baby’s tummy can hold:
Before birth baby never feels hunger as he is fed constantly via the placenta. After birth small frequent feedings help baby transition to an intermittent feeding pattern. To make this transition easier for baby mother’s breasts provide small amounts of milk (colostrum) on day 1.
Newborn stomachs don’t stretch. Zangenet al (2001) found that on day 1 a newborn’s stomach wall is firm and doesn’t stretch. By day 3 the stomach starts to expand more easily to hold more milk. Interestingly day 3-5 is when the milk volume starts to increase for most mothers.
When breastfeeding is going as expected each day baby feeds more effectively. In response mother’s milk production increases and baby gets more milk, which encourages her to feed more effectively. Supply follows demand
Day 1: baby’s stomach holds 5-7 ml (1 – 1.4 teaspoons) at a time. The mother will produce about 37 ml (one ounce) of milk/colostrum in the first 24 hours. The capacity of a newborn’s stomach is influenced by birth weight however the differences are not substantial.
1st week: with frequent feedings milk production increases to about 280 -576 ml (10-19 ounces) per day by day 7. Baby’s stomach can now hold 30-59 ml ( 1 -2 ounces) at a feeding by the end of the week.
2nd & 3rd week: with frequent feedings mother’s milk supply continues to build. Now baby’s stomach can hold 59 – 89 ml (2-3 ounces) at a feeding and baby is taking in 591-750 ml (20-25 ounces) per day.
4th & 5th weeks: babies will now be taking an average of 89-118 ml (3 -4 ounces) per feeding and daily milk intake will be in the range of 750 – 1035 ml (25 – 35 ounces) per day.
At one month most mothers will be producing nearly as much milk as their baby will ever need. Because the rate of growth slows as babies get older they continue to need about the same amount of breastmilk per day from one month to six months of age. The nursing pattern will change during that time even though the volume of intake over the day remains much the same.
Some people have trouble visualizing stomach capacity so using common objects can help make the capacity clearer:
Day 1: 5-7 ml is about the size of a large marble or a cherry
Day 3: 22-27 ml is about the size of a ping pong ball or a walnut
One week: 45-60 ml is the size of an apricot or plum
One month: 80-150 ml is about the size of an large chicken egg
Adult stomach size is equivalent to a soft ball or the size of your own fist clenched at rest and has a capacity of 1-4 liters.
When someone asks you why your newborn is nursing at least 10-12 times in 24 hours and suggests that your milk might not be filling up her tummy you now have some information to help them understand that frequent feedings, on baby’s own schedule, is exactly what her tummy and your milk supply need.
If you have any questions or concerns about your milk supply or other breastfeeding challenges please contact a Leader