Laying to Rest a Breast-Feeding Myth

A recent study (VJ Flaherman et al. J Pediatr 2018; 196: 84-90) examines whether early limited formula feeding undermines breastfeeding.

Background: The authors note that women have been discouraged from using formulas for newborns during the birth hospitalization due to concerns that this will diminish the frequency/success of breastfeeding.

Besides the concern that supplemental formula could increase the risk of breastfeeding cessation, some have expressed concern that supplemental formula could undermine benefits of breastmilk on the intestinal microbiome.  In addition, some have worried that if mothers perceived formula-feeding to be easier, that this could lower satisfaction with breastfeeding.

Yet, on the other side of the ledger, there are “about 80,000 newborns who require readmission after discharge” with the majority related to dehydration and hyperbilirubinemia.  Both of these conditions could be ameliorated by formula supplementation.  Thus, to address whether supplemental formula may be of benefit, the authors devised an “early limited formula” (ELF) trial.  The authors only enrolled infants >2500 gm and who had a weight loss >75th percentile on The Newborn Weight Tool (www.newbornweight.org). The authors excluded those with >10% of their birth weight due to routine practice of supplementation.

Methods: 163 mother-infant pairs were randomly assigned to either ELF along with breastfeeding or breastfeeding exclusively.  ELF involved giving infants 10 mL of a hydrolysate formula with a feeding syringe after each breastfeeding until the onset of copious breast milk

Key findings:

  • Mothers using ELF averaged 5.4 times/day for a median of 2 days.
  • Breastfeeding rates at one month of age: 86.5% of ELF group and 89.7% of controls; 54.6% of ELF and 65.8% of controls were breastfeeding exclusively at 1 month of age.
  • Readmission occurred in 4 (4.8%) of control infants and none of the infants in the ELF cohort (P=.06)
  • Using a subset of 15 (8 with ELF), the authors did not identify significant changes in microbiome of ELF group compared with the exclusively fed group when examined at 1 week and 1 month (as well as baseline)

Limitations of this study include the relatively small number of participants.  Furthermore, some populations that are at increased risk for breastfeeding cessation, namely mothers <25 years and African-American mothers were underrepresented.

My take: This study indicates that ELF is safe and does not appear to significantly increase breastfeeding cessation.

Related blog posts:

Why We Should Not Worry That Much About Water Intake

A recent article in the NY Times rebuts the claim that so many kids are dehydrated: No, You Don’t Have to Drink 8 Glasses of Water a Day

An excerpt:

Prospective studies fail to find benefits in kidney function or all-cause mortality when healthy people increase their fluid intake. Randomized controlled trials fail to find benefits as well, with the exception of specific cases — for example, preventing the recurrence of some kinds of kidney stones. Real dehydration, when your body has lost a significant amount of water because of illness, excessive exercise or sweating, or an inability to drink, is a serious issue. But people with clinical dehydration almost always have symptoms of some sort….

This summer’s rash of stories was inspired by a recent study in the American Journal of Public Health. Researchers used data from the National Health and Nutrition Examination Survey from 2009 to 2012 to examine 4,134 children ages 6 to 19. Specifically, they calculated their mean urine osmolality, which is a measure of urine concentration. The higher the value, the more concentrated the urine…

But as people in this country live longer than ever before, and have arguably freer access to beverages than at almost any time in human history, it’s just not true that we’re all dehydrated.

Some of the key points:

  • Much of the research suggesting that there is an epidemic of under hydration is being funded by companies with a financial interest
  • Water is contained in both foods and other beverages
  • The research standard of urine osmalality >800 mOsm is not used clinically
  • There are no documented health advantages that have been identified in individuals who drink more fluid (except in those with documented history of kidney stones)

Related blog posts: