One of the really excellent points that have come up in the
recent discussions of medicine failing breastfeeding is an appreciation that
human breasts, like all other organ systems, can have physiological dysregulation
and difficulties. There are a small percentage of women with physiological
inability to produce milk (estimated at 2-5% of the population), just as there
are individuals with beta cell dysfunction (Type 1 diabetics), thyroid issues,
and problems with really every other organ in the body. By comparison,
including types 1 & 2, the incidence of diabetes was 8.3% in 2011 (CDC,
2011). To put it simply, breasts are organs, and have about the same rate of
physiological issues as other organs (I borrowed this from the ongoing
conversations).
However, there has been a tremendous increase in recent
years in the number of women diagnosed with insufficient milk syndrome (or
insufficient milk supply syndrome) or “low milk production”. While there was an overall consensus the
problem was becoming more common, concrete data were hard to find. The best I can do is the Infant Feeding
Practices Study from 2006, wonderfully indexed on http://www.cdc.gov/ifps/results/. I
recommend checking it out, as you can see tables for every possible variable
and even download the raw data. But, here are the numbers:
|
Month stopped
breastfeeding
|
||||
Reason for stopping breastfeeding 3
|
< 1
|
1 to 2
|
3 to 5
|
6 to 9
|
>=9
|
My baby had trouble
sucking or latching on
|
53.7
|
27.1
|
11
|
2.6
|
1.5
|
Breast milk alone did not
satisfy my baby
|
49.7
|
55.6
|
49.1
|
49.5
|
43.5
|
I thought that my baby
was not gaining enough weight
|
23
|
18.3
|
11
|
14.1
|
8.4
|
A health professional
said my baby was not gaining enough weight
|
19.8
|
15.2
|
8.6
|
9.9
|
5
|
I had trouble getting the
milk flow to start
|
41.4
|
23.2
|
19.6
|
14.6
|
5.7
|
I didn't have enough milk
|
51.7
|
52.1
|
54
|
43.8
|
26
|
Table 1: Reasons for breastfeeding cessation, as reported by
US women participating in the 2005-06 Infant Feeding Practices Study. More than
2500 women participated in the initial survey; approximately 1400 women
completed the survey through the first year (Shealy et al., 2008).
I think, based on the numbers presented above, it is
reasonable to say that of the number of women who stopped breastfeeding during
the first five months of life, more than 50% identified insufficient milk
supply as a contributing factor. While this is not an overall incidence, it
does support the overall idea that IMS is increasingly common. We can also not know the number of women who
were told this by a medical professional versus self-diagnosed. If we use
medical diagnosis of poor infant weight gain as a measure of medical diagnosis
(again, not ideal) we end up with 8.6-19.8%. Still, much higher than the 2-5%
who likely have actual insufficient milk supply.
There are numerous physiological conditions that are
associated with decreased milk supply, and we cannot discount that the increase
in the incidence of these conditions may be contributing to the increase in the
number of women with insufficient milk syndrome. These conditions include:
polycystic ovarian syndrome; maternal postpartum hemorrhage, retained
placenta/placental fragments, thyroid conditions, insufficient glandular tissue
(Anderson 2001; Willis and Livingston, 1995; Speller and Brodribb, 2012; Neifert
et al., 1985 – in topical order), and mammary reduction, although this is not
an exhaustive list (refs). Other conditions, such as obesity and diabetes may
also interfere with lactation (Turcksin et al., 2012), particularly the onset
of milk production, known as lactogenesis (Nommsen-Rivers et al., 2010).
However, while these biological conditions may explain the
initial 2-5%, and perhaps a small increase in the incidence of these
conditions, it is unlikely they explain the dramatic difference we see in Table
1, with more than 50% of women who stop breastfeeding by five months reporting
problems with supply. Based on the 2009
Healthy People Data (released in 2012), 76.9% of women are initiating
breastfeeding and 47.2% of infants are breastfed to 6 months! So of the babies
who start breastfeeding, 61.4% are still breastfeeding at 6 months (but only
47.2%) of all infants. And, extrapolating from the 52.6% (average over the 3
categories) of women who report lack of milk as a reason for breastfeeding
cessation, we end up with a crude estimate of 32.3% for IMS. Again, this is a crude
estimate based on linking several different sources of numbers together and
should be considered an approximation, not a set in stone number and should be
viewed as a “back of the envelope calculation”. I’m using it as it is better
than anything else I can find (if you know of something let me know and I will adjust
the post accordingly).
So, we have an estimated occurrence of IMS at 32.3% compared
to an estimated biological frequency of 2-5%. That’s an excess of 27.3-30.3% women
reporting low milk supply. Add in the nearly 4 million infants born in the same
year, and we’re talking about more than 1 million women identifying with low
milk supply.
It seems unlikely then, that this difference can be
explained only by physiological issues, even adding in possible physiological
factors with infants as well, including tongue tie (Kumar and Kalke, 2012),
palate, latch, or vacuum issues (Geddes et al., 2008; Geddes et al., 2012). Certainly,
it would be an oversight to suggest that these factors are not very real, not
uncommon, and not contributing to overall increases in IMS. But these factors
along cannot explain the difference.
Difficulties with breastfeeding, including poor latch, poor
positioning, pain, nipple confusion, nipple cracking/bleeding, mastitis, are
very real realities for breastfeeding mothers. How many of these issues are the result of
limited exposure to other breastfeeding women and a medical community largely
unfamiliar with breastfeeding issues? Osband et al., (2011) reported that
pediatric residents in the United States received an average of 9 hours of
breastfeeding education (over a 3 year residency). Anchondo et al., (2012), in
a survey of pediatricians, obstetricians, gynecologists, and family medicine
physicians, reported that although physicians in their study had positive
attitudes towards breastfeeding and information on the health benefits,
hands-on knowledge was considerably lacking. Physicians also reported low
breastfeeding rates and short durations themselves. Freed (1995) in a survey of
more than 3000+ medical residents and physicians (68% response rate) reported
that while 90% endorsed breastfeeding, less than 50% felt like they had the
skills for counseling mothers. And the scariest information: for treating
jaundice, clinical management was wrong more than 50% of the time and for
insufficient milk syndrome, wrong about 30% of the time.
Nine hours of training, and probably a little extra (maybe a
half day at most) of training during medical school, is the sum total of the
“average” physicians training in breastfeeding. I would suspect too, that some
of that medical school time is allocated towards mammary anatomy (not that this
is not important for understanding how breastfeeding works). And the vast
majority of that time will probably be fair more theoretical than hands
on/practical, if the reports from Anchondo et al., (2012) are any indication.
The lack of training, and the invisibility of possible
issues related to breastfeeding, may be contributing to those excess sufferers
of IMS. How many physicians for example, upon hearing that a woman has “low
milk supply,” will address the feeding and not the supply issue? One of the most common “treatments” for low
milk supply is to supplement the infant with formula. Here, the focus is on the
infant, and meeting the metabolic needs of the infant, without thinking about
how the situation could be addressed from the maternal side. Milk production is driven by milk removal and
suckling from the breast. A complex series of hormones and neuropeptides
regulate milk synthesis, and include Feedback-inhibitor of lactation (FIL),
oxytocin, and prolactin. Suckling stimulates prolactin release, and while
plasma prolactin does not scale to milk synthesis rate (Cox et al., 1999),
prolactin promotes mRNA synthesis and the production of milk proteins. More suckling stimulates more prolactin and
maintains circulating plasma levels and milk synthesis (Cregan et al., 2002).
FIL works in a different manner – FIL accumulates in milk as feeding intervals
increase and the breast becomes increasingly full; increasing FIL down regulates
milk synthesis within the mammary epithelial cells (Peaker et al., 1998).
By providing the infant with formula, the entire process
above is interrupted. Infant hunger is
met by formula and the amount of time spent on the breast, actively sucking,
decreases. The decrease reduces the secretion of prolactin, accumulating milk
increases local FIL and milk synthesis is down regulated. Production decreases, increasing the need for
formula because the mother is now making less milk. It becomes a
self-fulfilling prophecy and compounds issues that may or may not have been
present. The ideal solution here would be to use the system, not disrupt it.
Instead of supplemental formula, increase the frequency and duration (a minimum
of 3-5 minutes) of the feeds. Not enough
milk? Feed more – in most cases, the body will respond accordingly. If it does
not, and the infant starts losing weight, then there is likely more
troubleshooting needed. But here, the clinical practice (30% of the time) is a
wrench in the physiology and likely contributes to further development of low
milk supply. Poor clinical management may not explain all instances of low milk
supply, but it cannot be discounted as a major player.
Thus far, we have been limited the emphasis to frequently
used clinical strategies for managing self- perceived low milk supply. Here,
perception of low supply has driven a specific treatment; this has further
contributed to the problem. And that is
just clinical management – what about other common problems influencing
breastfeeding, on both the mother and the baby’s side of things, that
contribute to low milk supply?
Next time (week): tongue tie, poor latch, and other breastfeeding
challenges . . .
References
Anchondo I, Berkeley L, Mulla ZD, Byrd T, Nuwayhid B, Handal
G, Akins R. (2012) Pediatricians', obstetricians', gynecologists', and family
medicine physicians' experiences with and attitudes about breast-feeding. South
Med J. 105(5):243-8.
Anderson AM. (2001) Disruption of lactogenesis by retained
placental fragments. J Hum Lact 17(2):142-4.
Cox DB, Owens RA, Hartmann PE. (1996) Blood and milk
prolactin and the rate of milk synthesis in women. Exp Physiol. 81(6):1007-20.
Peaker M, Wilde CJ. (1996) Feedback control of milk
secretion from milk. J Mammary Gland Biol
Neoplasia 1(3):307-15.
Cregan MD, Mitoulas LR, Hartmann PE. (2002) Milk prolactin,
feed volume and duration between feeds in women breastfeeding their full-term
infants over a 24 h period. Exp Physiol. 87(2):207-14
Freed GL, Clark SJ, Lohr JA, Sorenson JR. (1995) Pediatrician
involvement in breast-feeding promotion: a national study of residents and
practitioners. Pediatrics 96(3 Pt
1):490-4.
Geddes DT, Langton DB, Gollow I, Jacobs LA, Hartmann PE,
Simmer K. (2008) Frenulotomy for breastfeeding infants with ankyloglossia:
effect on milk removal and sucking mechanism as imaged by ultrasound. Pediatrics
122(1):e188-94. doi: 10.1542/peds.2007-2553.
Geddes DT, Sakalidis VS, Hepworth AR, McClellan HL, Kent JC,
Lai CT, Hartmann PE. (2012) Tongue movement and intra-oral vacuum of term
infants during breastfeeding and feeding from an experimental teat that
released milk under vacuum only. Early Hum Dev. 88(6):443-9. doi: 10.1016
Infant Feeding Practice Study II. http://www.cdc.gov/ifps/results/,
accessed Jan 24, 2013. Page last updated October 1, 2009.
Kumar M, Kalke E. (2012) Tongue-tie, breastfeeding
difficulties and the role of Frenotomy. Acta Paediatr. 101(7):687-9.