Where does fore-milk end and hind-milk begin (and does it actually matter?)

March 3, 2009 — Elizabeth Jay

milk-creamAccording to the World Health Organization, breastfeeding provides all the nutrition your baby requires for the first six months of life. This entails satisfying both hunger and thirst, and to meet both these needs you might have heard that your breasts produce two distinct types of milk: thin, watery ‘fore-milk’ to quench thirst; and creamy, calorie-rich ‘hind-milk’ to satisfy hunger.

These apparently different types of breast milk are described in various ways, but a distinction is generally drawn between a watery/creamy consistency, and thirst/hunger. There is also an implication that you need to make sure your baby gets enough hind-milk in order to gain weight. According to DrPaul.com:

‘Foremilk is the milk which is first drawn during a feeding. It is generally thin and lower in fat content, satisfying the baby’s thirst and liquid needs.
Hindmilk is the milk which follows foremilk during a feeding. It is richer in fat content and is high in calories. The high fat and calorie content of this milk is important for your baby’s health and continuing growth.’

ParentingWeb.com carries a similar description:

‘Foremilk, a bluish-white milk that is lower in fat than the hindmilk is the milk your baby receives in the first part of the feeding.
The hindmilk, which follows the foremilk, is richer and higher in fat than the foremilk. The hindmilk provides most of the nutrients your baby needs to gain weight and grow, and it satisfies his hunger.’

Valorie Delp on Families.com goes a step further, and says you can actually see the difference between the two:

‘If you’re really into science, pump a bottle of milk and let it sit out on the counter for awhile. You’ll see the milk separate into two distinctive layers. . .one being much fattier than the other. That’s hind milk and foremilk.’

Valorie’s demonstration is appealing, but it’s unfortunately some way off the mark. The separation she describes is simply the fat in the milk rising to the surface, not a different type of milk. This illustrates quite neatly the problem with using the terms ‘fore’ and ‘hind’: it reinforces the impression that the breast produces two types of milk, when in fact it makes only one. The descriptions shown above aren’t entirely inaccurate – milk does indeed change consistency during a feed – but this happens gradually, rather than suddenly.

The change occurs due to an increase in the fat content of the milk as a feed progresses – hence the ‘creamy’ label attached to hind-milk. It isn’t simply the case of the longer the feed, the fattier the milk, however. A study published in Experimental Physiology demonstrates that the fat content is related to the ‘emptiness’ of the breast: the less milk it contains, the greater the proportion of fat in the milk1. This means that if a baby has a 4oz feed when the breast is only storing half its potential milk volume, it will contain more fat than a 4oz feed taken when the breast is three-quarters full.

The amount of fat in your milk therefore varies considerably throughout the day, depending on the time since the last feed, the amount of milk consumed at the last feed, the amount of milk consumed at the current feed… It sounds complicated – how on earth do you make sure that your baby is getting enough? The short answer is that you don’t need to. Whilst fat is an important constituent of your baby’s diet, so are protein and carbohydrate, and both of these are found in the watery rather than the fatty part of the milk. The evidence also suggests that weight gain is related simply to the volume of milk consumed, and not its fat content2, underlining the nutritional importance of all the components of breast milk.

If you are breastfeeding on demand, the bottom line is that you don’t need to worry about the ‘type’ of milk your baby is getting. Babies can show a wide variety of feeding patterns, suckling for varying lengths of time and at varying intervals over the course of a day, and maintain a healthy weight3. The terms ‘fore-milk’ and ‘hind-milk’ do have their place: in scientific studies, they are used to describe the samples of milk taken at the beginning and end of a feed. In more general usage, however, they often produce a confused and inaccurate picture. They split milk into two types (when there is actually only one), and imply that the fat contained in milk is somehow more nutritious than the rest of it. In fact, nutrients that are important for health and growth are contained in both components of breast milk, so the implication that the fatty part is for ‘eating’ and the watery part for ‘drinking’ is somewhat misleading. The important thing to remember is that ensuring your baby’s thirst and appetite are satisfied is not a complicated undertaking – it’s simply a matter of letting her feed when she wants to.

  1. Exp Physiol. 1993 Nov;78(6):741-55.
  2. Paediatr Perinat Epidemiol. 2002 Oct;16(4):355-60.
  3. Pediatrics. 2006 Mar;117(3):e387-95.Click here to read
Posted in Fore/hind milk, Research. Tags: , , , , , , , , , . 40 Comments »

Milk stasis – not infection – is the main cause of mastitis

February 24, 2009 — Elizabeth Jay

holding_babyPrior to my brush with it, I thought that mastitis was caused by a bacterial infection. This is not completely unreasonable, given that this is precisely how numerous ‘health’ websites define it (FreeMD, eMedicineHealth, HealthSquare to name just a few). When you consider that the symptoms of mastitis can include a fever as well as redness, lumps and pain in the breasts, and treatment can involve antibiotics, the definition seems to make sense.

Unfortunately, it turns out to be somewhat misleading. Whilst bacterial infection may play a part in mastitis, it is in fact inflammation of the breast tissue that is at the root of the condition, and causes the majority of the symptoms. The World Health Organization describes mastitis as ‘an inflammatory condition of the breast, which may or may not be associated with infection’1. They summarize the uncertain relationship between bacterial infection and mastitis as follows:

Many lactating women who have potentially pathogenic bacteria on their skin or in their milk do not develop mastitis.
But:
Many women who do develop mastitis do not have pathogenic organisms in their milk.

This basically means that you can be carrying the bacteria associated with mastitis – and even have it in your milk – without developing the condition, and conversely, you can succumb to mastitis when there is no evidence you’re carrying the bacteria.

So, if mastitis isn’t due to an infection, what does cause it? It appears that the inflammation that characterizes mastitis is a consequence of ‘milk stasis’: milk is produced, but then remains in the breast, rather than coming out during feeding. Milk stasis can occur for many reasons, including blockages in the ducts, a decrease in feeding frequency and poor attachment1,4. It’s also possible that stress might play a role, by both increasing milk production and delaying the letdown reflex2. Why milk stasis goes on to cause inflammation isn’t so clear, though it could result from inflammatory substances found in milk irritating the breast tissue, or an immune reaction to certain milk proteins3.

Although bacterial infection is not often the primary cause of mastitis, it is sometimes thought to exacerbate the symptoms3. Determining the precise role it plays, however, is a tricky business. Firstly, it is very hard to ensure that milk cultures are sterile, so it isn’t always possible to know that the bacteria found in a woman’s milk haven’t in fact come from her skin when the sample was taken1. Secondly, as stated above, harmful bacteria can be found in the milk of women who don’t have mastitis, indicating that there is not a simple cause and effect relationship between the two. One possibility is that mild changes initiated by milk stasis may be exacerbated by bacterial activity: symptoms could be considered to be on a scale, from a reduction in milk output but no pain (known as subclinical mastitis), to breast abscess and severe pain, with increasing amounts of bacterial involvement as you move from one end to the other3.

What does all this mean if you find yourself suffering from mastitis? Perhaps the most important thing to remember is that the symptoms are probably due to a milk flow problem, so your top priority should be to address any causes of this. This might include making sure your baby is properly latched on, feeding more frequently and emptying the breast properly at each feed. Many doctors also choose to treat mastitis with antibiotics, although there is a lack of consensus as to which ones to use, and even whether it’s appropriate to use them at all (see when should mastitis be treated with antibiotics?). Whether or not you take medication, the most important thing is to keep the milk moving. Whilst feeding with mastitis doesn’t appear to pose a risk to you or your baby, stopping could well do: not only will it make the symptoms worse, but it will almost certainly jeopardize your milk supply5. Mastitis is a common reason for giving up breastfeeding, but it needn’t be – focus on sorting out your feeding technique and you should hopefully make a rapid recovery.

  1. Mastitis: causes and management. World Health Organization; 2000.
  2. Mediators Inflamm. 2008;2008:298760.
  3. Arch Dis Child. 2003 Sep;88(9):818-21
  4. Cochrane Database Syst Rev. 2009 Jan 21;(1):CD005458.
  5. Am Fam Physician. 2008 Sep 15;78(6):727-31.
Posted in Mastitis, Research. Tags: , , , , , , , , , , , , , , , , , . 3 Comments »

Breast shells: preserving your modesty

February 15, 2009 — Elizabeth Jay

shellsWhen I suffered substantial nipple damage in the early weeks of breastfeeding, the ‘moist wound healing’ route didn’t prove effective (see nipple solutions 1: doing nothing), so allowing a bit of air to circulate was the obvious alternative option. Walking around topless wasn’t always practical (although I have to admit it happened quite a bit – apologies to my neighbours) so wearing breast shells provided a workable solution. They seemed to help, psychologically at least, but as I used them on both breasts pretty much all the time, I have no idea whether they really had any effect on the healing process, or the pain I experienced when breastfeeding.

Is there any clinical evidence of their effectiveness? The short answer is not really, although that may be partly because there is very little research looking at the use of breast shells in this context. A couple of studies have reported on the effect of shells used in combination with lanolin, but they obviously don’t tell us anything about the utility of shells in keeping nipples dry12.

There is one small study, conducted some time ago, which evaluated the use of breast shells on their own as a means of alleviating nipple pain3. 20 women who had just started breastfeeding and were experiencing pain were asked to wear a single breast shell whenever they weren’t feeding (the other nipple was kept shell-free, to serve as a control). On the second and fifth days of using the shells the women were asked to rate the level of pain they were experiencing on a 5 point scale, from mild (1) to excruciating (5) during the first two minutes of a feed, and for the period between feeds. Although the mean pain score was higher for the nipple without the shell on day five, this difference was not statistically significant. The study did have an interesting anecdotal result, however. Despite the fact that the shells didn’t lessen pain, 80% of the women said they would consider using them again, so the majority of women felt that they offered some kind of help. The precise nature of the benefit isn’t described in detail, but it appears to be related to improved general comfort and decreased friction with clothing.

Problems mentioned by some women (although it is not reported how many) focused on concerns about the ‘hardness’ of the shell, and the pressure it exerted on breast tissue. The possibility of pressure on milk ducts is also mentioned by shell manufacturers, who advise against using breast shells for extended periods (although they also market the same action as a short term means of relieving engorgement). Whilst the possibility of negative consequences arising from pressure caused by shells can’t be dismissed, there don’t yet appear to have been any reported in the clinical literature, so the extent to which a problem actually exists isn’t clear.

The lack of research in general into either the benefits or drawbacks of breast shells makes it difficult to draw any firm conclusions regarding their use. Whilst problems arising from pressure on breast tissue cannot be dismissed, as yet, these have not been widely reported. There isn’t any data showing they improve nipple pain, although there is anecdotal evidence that they ease discomfort.  You may find they take up too much room in your already overstretched bra, or you might find the way that they stop it rubbing against your nipples provides a little relief. If the latter is the case, breast shells do have one undeniable advantage: they allow you to minimize friction, without having to resort to indecent exposure…

  1. Arch Pediatr Adolesc Med. 1998 Nov;152(11):1077-82.
  2. J Perinat Educ. 2004 Winter;13(1):29-35.
  3. J Nurse Midwifery. 1988 Mar-Apr;33(2):74-7.
Posted in Breast shells, Nipple problems, Research. Tags: , , , , , , , , , , . 1 Comment »

Will breastfeeding leave you with a little less lift?

February 13, 2009 — Elizabeth Jay

smug_mumGiven the number of celebrities who have recently publicized their decision to breastfeed (Angelina Jolie, Christina Aguilera and Jennifer Garner to name but a few), it was disappointing to read in February’s British Vogue that Cheryl Cole is put off by the effect it might have on her breasts. ‘I want to breastfeed,’ she declared, ‘but I’ve seen what it can do, so I may have to reconsider.’

Cheryl’s concern is a common one. Whilst breastfeeding may be the healthiest option, it isn’t seen as the aesthetically pleasing one: not only does it desexualize your breasts (using them for something other than attracting men – surely not!?), it is also rumoured to leave you with a little less ‘lift’ than you might have had if you’d gone down the formula route.

Is a little sagginess really the price you have to pay for giving your children the healthiest start in life? Not necessarily, according to a recent study by a plastic surgeon at the University of Kentucky1. The surgeon and his colleagues examined data from all the women who had come to the UK HealthCare clinic seeking aesthetic breast surgery over an eight year period. They considered a number of factors, including the number of pregnancies the women had had and whether they had breastfed, and determined the degree of ‘ptosis’ (that’s droop to you and me) from pre-operative photos.

Factors which appeared to increase ptosis included higher body mass index, pre-pregnancy bra size, age, and smoking. The number of pregnancies a woman had gone through was also linked with ptosis, but whether she had breastfed, interestingly, was not.

So it seems that although having children may leave you less perky (probably in more ways than one), you can breastfeed safe in the knowledge that any loss of elasticity has already happened either in pregnancy or in the days shortly after giving birth. Cheryl, bear this in mind if you’re thinking about having children, and if you’re really worried, consider adopting. In the meantime, it might be sensible to give up smoking…

  1. Aesthet Surg J. 2008 Sep-Oct;28(5):534-7.
Posted in Ptosis (sagging), Research. Tags: , , , , , , , . Leave a Comment »

Insufficient milk: all in the mind?

February 11, 2009 — Elizabeth Jay

milk pouring from bottle to glassIf you’ve ever felt that your baby isn’t satisfied with your breast milk, you’re not alone: ‘not enough milk’ is the reason mothers provide more than any other for giving up on breastfeeding1. A recent review in the Journal of Nursing Scholarship reports that the problem is huge2: Insufficient Milk Supply (IMS) is the primary cause of 35% of instances of early breastfeeding termination. If we apply this figure to the UK, where 51% of women start breastfeeding initially, but have stopped by 6 months3, it equates to an alarming 1 in 6 babies being potentially malnourished, were it not for the option of formula milk.

Or does it? The review, which collates the research in this area over the last 10 years, reveals that the term IMS is actually used interchangeably with PIM – Perceived Insufficient Milk – making it very difficult to determine how many women really aren’t providing enough milk for their babies, as opposed to those who just believe they aren’t.

Although research in this area is lacking (according to the review, ‘the accuracy of maternal perceptions, or PIM, in relation to actual milk supply has not been determined’), there is some data that gives an idea of the relationship between the two. A study conducted in Chicago followed 96 mothers who planned to exclusively breastfeed for at least 12 weeks4. To determine how much milk their babies were taking on board, the women were asked to weigh them before and after every feed and record the results in a log book. Whether or not the women thought their milk supply was adequate was determined in a series of telephone interviews.

Unfortunately, the paper doesn’t report exactly how the mothers’ perception of their milk supply related to their actual output (the goal of the study was to identify factors that predicted whether women were breast or formula feeding at 12 weeks). It is, however, possible to work out roughly from the data they do include that at least 17% of the women whose supply was adequate at the final recorded weighing session went on to report PIM in the interview two weeks later. Whilst the possibility that the milk supply of all these mothers suddenly dropped cannot be ruled out, neither can the possibility that it was the perception of their supply, rather than their actual supply, which suffered.

One thing that the Chicago study did demonstrate strongly, as did the other research in the review, is that if women think they aren’t producing enough milk (regardless of how accurate this perception is), they are more likely to stop breastfeeding, or supplement with formula. The study also showed that the women most likely to report PIM (and to have a genuinely inadequate supply) were those who breastfed their babies fewer than 8 times a day. As breastfeeding regularly is itself vital to maintain production1, anything that compromises this (such as formula supplementation) can quickly reduce supply, turning the perception of insufficient milk into a reality. If you’re genuinely worried, you should see your doctor. In the meantime, keep in mind that the best way to stop supply dwindling is to increase, rather than decrease, the frequency of your breastfeeding.

For further information about this problem, see not enough milk: the ‘symptoms’ you don’t need to worry about.

At the end of the study (12 weeks postpartum), 28 mothers were using formula either completely or partially, and 69 were breastfeeding exclusively. At week 6, (when actual milk output was calculated for the final time), 19 of the formula feeders, and 65 of the breastfeeders were shown to have an adequate supply. In the 8 week interview, however, 20 of the formula feeders and 6 of the breastfeeders reported PIM, which means that assuming that the 13 women whose supply was genuinely low at week 6 reported PIM at week 8, the other 13 mothers (11 formula feeders and 2 breastfeeders) perceived their supply to be low when not long before it had been shown to be fine. Unfortunately, as the measures of actual and perceived insufficiency weren’t taken at the same time, it isn’t possible to work out exactly how much of the insufficiency is imagined rather than real (more research in this area please!). On the plus side, 6 women who reported PIM at week 8 were breastfeeding exclusively at week 12, so it isn’t impossible to overcome this problem.

  1. Aust Fam Physician. 2006 Sep;35(9):686-9.
  2. J Nurs Scholarsh. 2008;40(4):355-63.
  3. Infant Feeding Survey 2005
  4. J Perinat Neonatal Nurs. 2007 Jul-Sep;21(3):250-5.
Posted in Insufficient milk, Research. Tags: , , , , , , , . 4 Comments »
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