low milk supply series, part 1: research

low milk supply breastfeeding research

As I’ve mentioned in the past, I did my Masters degree on U.S. mothers and low milk supply.  When I started my research I thought there must be studies out there that would show exactly how many families deal with low supply.

I expected to unearth some sort of perfect algorithm.  My ultimate goal was to develop a tool that could help parents quantify their milk production, and get immediate customized help if needed.

But I never made that tool, and I never found that algorithm.  Why?  Because it turns out there’s very little solid, reliable research out there on low milk supply.

For the most part, “low milk supply” is a symptom, not a diagnosis.  We know of plenty of situations that can cause low milk supply, like insufficient glandular tissue, or infrequent or insufficient milk removal, or oral or muscular issues in the baby, or thyroid problems in the nursing parent, or previous breast reduction or other surgeries, or retained placental fragments… the list goes on.

The thing is, we don’t really know how many parents are dealing with low milk supply.

the origins of “the mythical 5%”

There are some figures floating around- you often hear about what I call “the mythical 5%”- which, as best I could find, was traced back to a 1989 WHO (World Health Organization) publication that stated in industrialized countries, “a maximum in the range of 1-5% of women experience lactation failure on purely physiological grounds” (Akre, J. (1989). Health factors which may interfere with breast-feeding. WHO Bulletin Supplement, 67, 41-54.).

That statistic- on lactation failure due to the nursing parent’s physiology– not on any issues with the baby, or issues of breastfeeding management- is now repeatedly used incorrectly to claim that 5% of nursing parents have low milk supply.

Is it really only 5%?  I HIGHLY doubt it, but we don’t know, because it would be incredibly unethical to study low milk supply in a controlled setting without intervening. You can’t say “oh, you think your baby isn’t eating enough?  Let me lock the two of you in a lab for a week and study you, and watch the baby possibly lose weight and starve.”

When you find out a nursing parent is having trouble, you need to make sure that the baby is getting fed-whether it’s the parent’s milk, donor milk, or infant formula- because ignoring low milk production can have disastrous consequences.

In “Prevention of Breastfeeding Tragedies” (2001), Dr. Marianne Neifert discussed that parents may not recognize insufficient milk supply since they spend so much time with their babies and do not notice baby’s weight loss.  Often these babies become lethargic and sleepy- rarely crying or fussing- which parents can mistake for being a “good baby”.  As these babies become more and more dehydrated, they eat less and sleep more- what some professionals call being “content to starve.”

I run my practice on the #1 rule of being an IBCLC, which is FEED THE BABY (thank you, Linda Smith!).

low milk supply and survey data

What we DO have data on is whether parents think they have low milk supply.  It’s vitally important here that you understand me- I am not, not, NOT saying these parents are making things up.  I’m not saying low milk supply is a myth.  I’m not blaming anyone, I’m not casting doubt, I’m not accusing anyone of lying.  I’m simply talking about how many parents in the United States have reported that they didn’t make enough milk for their baby.

  • Studies in 2005 and 2009 found that the #1 reported reason for weaning is low milk supply (Wambach, K.,Campbell, S. H.,Gill, S. L., Dodgson, J. E., Abiona,T.C., & Heinig, M. J. (2005). Clinical lactation practice: 20 years of evidence. Journal of Human Lactation, 21, 245-258.) and (Mercer, J.  & Thulier, D. (2009) Variables associated with breastfeeding duration.  The journal of obstetric, gynecologic, & neonatal nursing. 38 (3), 259-268.)
  • A 1994 national study of WIC participants found that 55% of respondents felt they didn’t make enough milk for their babies, and 34% reported that their milk supply was low in the first month of baby’s life (Fein, S., Grummer-Strawn, L., Labiner-Wolfe, J., Scanlon, K., & Shealy, K. (2008). Characteristics of breastfeeding practices among US mothers. Pediatrics, 122, s50-s55.)
  • A 2005 survey of parents who stopped breastfeeding found that 45.5% of parents said they didn’t make enough milk, but only 11.7% of respondents reported that a health professional said baby wasn’t gaining well (Ahluwalia, I., Hsia, J., & Morrow, B. (2005) Why do women stop breastfeeding?  Findings from the Pregnancy Risk Assessment and Monitoring System.  Pediatrics, 116 (6), 1408-1413.)
  • A worldwide study found that approximately 35% of parents report that they weaned because they didn’t make enough milk, and between 30-80% of ALL nursing parents report not making enough milk at some point (Gatti, L. (2008) Maternal perceptions of insufficient milk supply in breastfeeding. Journal of Nursing Scholarship, 40 (4).  355-363.)

Do you see how none of these survey results are jiving with that mythical 5% figure?  The studies above report low milk supply concerns in a huge percentage of nursing families.  This is a problem.  A massive problem.  What on earth is going on here?  If the 5% is correct (and again, I don’t think it is) then where are the other reported 30-75% coming from?

Let’s dig deeper.

upcoming posts in the low milk supply series

In part 2 of this series, I’ll be discussing breastfeeding data sources from 1948 to present day and what it can teach us about low milk supply.  Did you know that MOST of the data we have from breastfeeding parents in the USA is thanks to infant formula companies?

In part 3, we’ll talk about health care providers and what they know about milk production and insufficient milk supply- and why this matters.

In part 4 (which may need to grow into part 4, 5 and 6) we’ll delve into what parents know about milk production, what they hear about milk supply, and what symptoms make them suspect low milk supply.


Stick with me, folks.  It’s gonna be a long, bumpy, milky ride.  If you want to take the trip with me, you can subscribe to my blog via email here.

subscribe to my blog!

I'll email you every time there's a new blog post.  No spam.  Pinky swear.

Sweet! Check your email...

11 thoughts on “low milk supply series, part 1: research

  1. I had the opposite issue of never having enough milk to begin with and was told I needed to supplement by two lactation consultants and the pediatrician because the baby’s weight was dangerously low after her first week of life. We were a complication free home birth, but on the third day post partum, I had this sneaking feeling that my milk wasn’t coming in even though I am a FTM and did not know what it would feel like exactly. My midwife said she thought it was and then it never quite did. I’ve had low supply since the beginning and can’t help wondering if I had pumped frequently during the first week of life if it would have helped me establish enough supply to EBF. We are 15 weeks postpartum and combo feeding for now, but I would really love some answers as to what happened since I had absolutely no risk factors and none of my health professionals have been able to explain to me why this happened. The more I speak to friends and gather anecdotal evidence (since the scientific data is so poor) I have noticed that every mom I know who has a sufficient supply started pumping immediately postpartum. I am wondering if is any scientific evidence to suggest that immediate postpartum pumping yields dramatically better results than using pumping to up supply after the first week of life? Any answers would be much appreciated as this still feels like a conundrum to me.

  2. Hmmm. This comment about eating after 5, leptin, etc may have some correlation. Some of my reading discussed women with lower BMI having higher prolactin levels and longer lactational amenorrhea period after childbirth. Perhaps there’s some correlation? Might want to discuss this.

  3. You have certainly done a lot of research! Something that I have come across that has worked for me is not eating after 5pm. The prolactin surge occurs between 12-2am. Ingestion of carbohydrates within 4 hrs of going to bed causes suppression of the prolactin surge. This phenomenon is well known in the body building community but I have not seen any applications towards lactation. My personal theory is that women who tend to experience more insulin resistance will experience this effect more profoundly. I know my own personal biology tends towards insulin resistance more readily during times of stress. I had plenty of milk for the first 10 weeks and then experienced a substantial drop. This one simple change of cutting off my eating at 5pm has single handedly brought my supply back. This phenomenon might explain why women have enough milk to start and then experience a drop. The relationship between prolactin insulin and leptin really needs to be explored in depth here. I hope this helps someone!

    1. Sarah this is really interesting, and nothing I’ve heard before. I fed fine as well for the first 12 weeks and then it all fell apart (and sadly I didn’t realise, for all the reasons Rachel describes above – she was a ‘good’ baby, and I didn’t notice that she wasn’t gaining). Do you think the 5pm rule only applies if you are feeding during the night? My bub is 7mo now and I am still doing everything I can to up my supply. She sleeps through the night now though.

    2. This is interesting, Sarah. I’m going to start doing some digging into leptin and prolactin. Thanks for sharing!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.