Breastfed infants who gain weight slowly can present a challenge to both parents and providers. Their quiet, content demeanor can delay diagnosis, and their anorectic behavior can make feeding very difficult. Moreover, as, Powers laments, our evidence base is clouded by confused definitions, contradictory growth standards, inadequate research, and no definitive standard of care.
The medical literature has long suggested that, at minimum, infants should be back to birthweight by 2 weeks of age, and thereafter grow at least 20 gm/day, or 5 oz/week. However, data from the 2006 WHO Multicenter Growth Reference Study challenge these minimal standards. WHO data put infants of all percentiles back to birthweight before a week of age, and thereafter even female infants growing along the 1st percentile average 28 gm/day over weeks 2 to 8, while 1st percentile boys average 32 gm/day. At the 50th percentile, girls average 34 gm/day, boys 39 gm/day.
Yet we do see exclusively breastfed babies who grow more slowly than the WHO standards. What’s going on?
It was over 25 years ago that Dewey et al demonstrated in their classic DARLING studies that healthy infants who breastfeed on demand self-regulate their intake to steadily gain weight appropriately However, as many have observed, the sleepy underweight infant cues subtly and infrequently, thus defeating feeding strategies which rely on the baby’s presumptive good appetite to increase both infant weight and maternal milk production. We submit that once the infant’s appetite is impaired, the infant is NOT the healthy infant Dewey and WHO describe. Instead, apparent anorexia makes the infant incapable of the self-regulation that could break the vicious cycles of slow growth, low energy, and infrequent ineffective feeds.3 Importantly, ineffective milk removal also slows maternal breast milk production, further decreasing infant intake.
In our breastfeeding medicine practice we’ve developed an approach to breaking these vicious cycles, using high-flow feeding methods to push infant intake towards rapid catch-up growth, while also offering strategies for increasing the rate of milk production. This requires significant maternal time, effort and energy, and can be hugely frustrating, so it is important to offer strategies that work with the mother’s real life, and permit her needed rest. Thus successful management also includes appropriate and intensive support to the mother, her energy, sleep, and emotional well-being.
It’s our observation that, once caught up on weight, these infants become easy to feed, and do indeed achieve appropriate self-regulation to follow WHO growth standards.