When mothers hear that colostrum is measurable in teaspoons rather than ounces, they often wonder if that can really be enough for their babies. The short answer is that colostrum is the only food healthy, full-term babies need. The following is an explanation:
A 1 day old baby's stomach capacity is about 5-7 ml, or about the size of a marble. Interestingly, researchers have found that the day-old newborn's stomach does not stretch to hold more. Since the walls of the newborn's stomach stays firm, extra milk is most often expelled (spit up). Your colostrum is just the right amount for your baby's first feedings!
By day 3, the newborn's stomach capacity has grown to about 0.75-1 oz, or about the size of a "shooter" marble. Small, frequent feedings assure that your baby takes in all the milk he needs.
Around day 7, the newborn's stomach capacity is now about 1.5-2 oz, or about the size of a ping-pong ball. Continued frequent feeding will assure that your baby takes in all the milk he needs, and your milk production meets his demands.