Home » Your Newborn’s Stomach Day 1-10Your Newborn’s Stomach Day 1-10 Ameda – The First 12 Months: Baby’s Stomach Capacity in First 10 Days www.ameda.com The chart below shows the average size of a newborn’s stomach and how much milk it can hold at birth. Now you can see why your colostrum, or early milk, is more than enough to fill your newborn’s tummy. kellymom.com :: Nursing your newborn – what to expect in the early weeks www.kellymom.com