Source: Unknown

Source: Unknown

If you’ve looked at almost any news source recently, you’ve probably seen the headlines proclaiming that formula actually helps moms breastfeed.  And if you’re like me or many others, you probably said, “What the…?” and started looking for more.  I’m not going to talk about what the media outlets report, but rather what the actual research suggests, as that’s what we ought to be dealing with.

What was the study


In a nutshell, researchers took 40 infant-mother dyads where the infant was at-risk of not being breastfed (but all of whom wanted to exclusively breastfeed) and provided small, measured amounts of formula to half of these infants until mom’s mature milk came in (the experimental group) or nothing except continued breastfeeding (the control group).  The researchers then followed up looking at breastfeeding or formula use at 1 week, 1 month, 2 months, and 3 months.  They found significant differences between the two groups in the amount of breastfeeding at all and exclusive breastfeeding at the 3-month (and earlier) follow-ups.  Notably, 95% of moms in the experimental group versus 68% of moms in the control group were breastfeeding at 3 months (80% vs. 47% were exclusively breastfeeding).

What are the issues?

The first thing that many articles are not discussing is that this study, as mentioned, was for infant at-risk of not being successfully breastfed, despite maternal intentions to breastfeed.  This was established using the criteria of only including babies who had lost more than 5% (but less than 10%) of their weight in under 36 hours.  There is research, as cited by these authors, that early, significant weight loss is associated with maternal anxiety about feeding and also one of the more commonly cited reasons women say they give up breastfeeding prior to 3 months.  The entire point of the study was to alleviate maternal anxiety about supply.  We’ll get back to this in a minute, because this is the crux of the issue to me, but I also wanted to bring up another key point that isn’t getting a lot of press in the popular media.

As many of you know, most research contradicts this, with early formula use linked to lower breastfeeding success, a topic the researchers are very clear to talk about because they actually do not believe that formula as it has been given out to women in the past is helpful.  The differences between previous studies and practice and this particular intervention is threefold.  First, the current intervention offered very small amounts of formula – 10mL only – after a breastfeed to ensure that the infants were not satiated by the formula and continued to want to breastfeed.  Second, they only administered formula by syringe – no bottles – so that infants would not get nipple confusion.  And finally, prior to beginning there was a clear time frame for this limited formula use; namely, mothers knew it would stop as soon as their mature milk came in.  So in many ways, what this intervention provided was not the typical bottles of formula given to moms, but rather a very calculated way to alleviate mom’s worry while providing the minimal amount of formula to the infant.

Source: Tracy Cassels

Source: Tracy Cassels

Getting back to the issue of anxiety – this is the key problem for me.  While I understand that the researchers are actually trying to help breastfeeding rates, it still is no good for baby given that it impairs the virgin gut which is key to developing many of the health benefits associated with breastfeeding.  (For a great review article on the virgin gut, check out The Alpha Parent’s piece here, and check out the science behind it all at Dr. Jay Gordon’s summary here.)  Even more than this, though, is that it’s addressing a problem by feeding into it.  By offering supplementation, parents’ anxieties are being confirmed – they aren’t making enough milk at first, their baby is hungry, etc.

Instead of this type of intervention, would it not be better to work on information interventions?  For example, we know that the use of an epidural is associated with greater weight loss in the first 48 hours (most likely due to artificial weight gain via excess fluids)[2], so providing mothers with a chart of what’s normal in terms of weight loss given their situation would be much more beneficial.  These “at-risk” infants lost an average of 6% of their weight, yet average weight loss for normal, term, breastfed infants is in the realm of 5.5%[2].  Only formula-fed babies show a very small weight loss on average (around 2.5%)[2].  So of course if we’re comparing infants to this non-biological ideal, women will be anxious.  Despite their babies being biologically normal.

Imagine if they actually increased the sample and simply measured weight loss and weight gain all while looking at the factors we know to influence this (i.e., birth weight, epidurals, etc.).  Then you measure them for a few weeks after to get a baseline later.  You offer support to the mothers during this time so they know they can continue breastfeeding (after all, these are women who want to breastfeed).  At the end of this, you have real data of the variability in weight loss but also hopefully good health status of all infants at the end of the couple week period.  This would give parents (not just mothers) the information they could use to feel comfortable that what they experience with weight loss is okay.  That they will get the breastfeeding thing down with support and not have to turn to formula early and often.

So will formula help you breastfeed?  In the measured way they administered it, possibly, if you’re at-risk of not breastfeeding due to higher than expected weight loss and anxiety associated with that.  But all this effect has done is alleviate mom’s anxiety.  There are better ways to do this that don’t involve formula, so why are we not looking at those (namely, just giving moms support and information)?  Especially when we know most people will not know exactly what was done here and will assume formula in a bottle to supplement might help when we know that’s not the case.


[1] Flaherman VJ, Aby J, Burgos AE, Lee KA, Cabana MD, Newman TB.  Effect of early limited formula on duration and exclusivity of breastfeeding in at-risk infants: an RCT.  Pediatrics 2013; DOI: 10.1542/peds.2012-2809.

[2] Martens PJ, Romphf L.  Factors associated with newborn in-hospital weight loss: comparisons by feeding method, demographics, and birthing procedures.  J Hum Lact 2007; 23: 233-41.