Infant stomach size
How big is baby’s belly?
Actually, we don't know the average size of a baby's stomach at birth! Researchers have been trying to measure infant stomach capacity for over 100 years. It's been estimated that a 40-week fetus swallows around 5-30ml of amniotic fluid at a time. Every baby has a different caloric requirement & exact volumes cannot be standardized because stomach capacity varies.
Why do we use grapes or eggs to help visualize the size of a baby's stomach? Guidelines help new parents navigate uncharted territory, learning your infant's feeding cues can be challenging, & breastfeeding isn't visual (you can't see how much your baby is transferring)
How do you know if your baby is getting enough? One study found that infant stomach capacity of 20 mL translates to a feeding interval of approximately 1 h for a term baby. This happens to correspond to the gastric emptying time for human milk, as well as the normal infant sleep cycle. Larger feeding volumes at longer intervals may be stressful and cause spitting up, reflux & hypoglycemia. Feeding & sleeping at 1-h intervals likely meet the evolutionary expectations of human neonates. Evolutionary anthropologists found the !Kung hunter-gatherers of Namibia & Botswana feed their babies on average four times an hour, with about 13 minutes between feedings from age 0 weeks to 2 1/2 years.
Bottom line: It's normal if your newborn eats 4-7 times in 1 hour, sleeps for 30 minutes, wakes up & wants to eat again. Your baby's ability to suck/swallow/breathe at the breast, the stretchiness of the stomach & the speed at which food gets digested are all part of the equation. Instead of watching the clock, watch your baby! A baby who is getting enough to eat comes off the breast on their own, has relaxed hands & plenty of wet & dirty diapers. It's possible (& normal) for your baby to lose 10% of their birth weight over the first 10-14 days before gaining weight. Let your baby show you how much they need to eat. If this feels overwhelming, it's because it is! It goes against modern culture & what we expect of newborns. We need a supportive community to make this picture work! If you need help sorting out what's normal newborn behavior vs. societal expectations, hit me up. I'd be happy to assist you!