Breastfeeding and thrush: the difficulty getting a diagnosis

stack-of-petri-dishesAlthough many lactation specialists agree that breasts are susceptible to thrush (the candida fungus) when a woman is nursing, others feel that the yeast infection is ‘overdiagnosed and overtreated1.’ A quick perusal of the Mumsnet discussion forum shows that some health professionals are prepared to go a step further, and deny it is a problem at all (see breastfeeding and thrush: it’s complicated).

The scepticism that thrush can interfere with breastfeeding exists because at present there is no absolute proof that candida is the root cause of breastfeeding pain. A mother can become colonized with candida but remain infection-free, or can display many of the symptoms commonly associated with thrush (such as red, shiny, flaky or burning nipples) but test negative for it in the laboratory2.

This doesn’t mean that thrush isn’t a problem however: there are several controlled clinical studies that point to an association – not a perfect one, but a significant one nonetheless – between the presence of candida and certain symptoms suffered by breastfeeding mothers.

Evidence that thrush can affect breastfeeding mothers

Support for this relationship was provided by a study that assessed whether mothers who tested positive for candida shortly after they had given birth went on to develop the symptoms of thrush2,3. Nipple swabs and milk samples that were taken from 100 women at their two week post-birth check underwent microbiologic culturing to test for candida, and women completed two interviews to determine whether they had symptoms associated with thrush: one at the time the swabs were taken, and another 7 weeks later.

Although there was no association between colonization and symptoms initially, 20 of the 23 women colonized by candida went on to develop at least one of the symptoms of thrush (burning nipples, stabbing breast pain, shiny and/or red nipples). The percentage of cases (breasts rather than mothers, as it’s possible to be affected on only one side) with a positive or negative candida result that developed symptoms are listed below.

Nipple culture results (22 positive cases, 178 negative cases):

  • 95% of positive cases and 49% of negative cases reported sore nipples
  • 100% of positive cases and 33% of negative cases reported burning nipples
  • 82% of positive cases and 18% of negative cases reported non-stabbing breast pain
  • 91% of positive cases and 24% of negative cases reported stabbing breast pain
  • 45% of positive cases and 11% of negative cases reported shiny nipples
  • 36% of positive cases and 13% of negative cases reported flaky nipples

Milk culture results (32 positive cases, 168 negative cases):

  • 78% of positive cases and 50% of negative cases reported sore nipples
  • 81% of positive cases and 33% of negative cases reported burning nipples
  • 72% of positive cases and 16% of negative cases reported non-stabbing breast pain
  • 81% of positive cases and 21% of negative cases reported stabbing breast pain
  • 41% of positive cases and 10% of negative cases reported shiny nipples
  • 38% of positive cases and 11% of negative cases reported flaky nipples

Every symptom occurred at a significantly higher rate in the cases where candida had been detected. Each symptom was also reported in several negative cases, however, indicating either that the mothers had become colonized by candida after the initial test, or that the symptoms were caused by something else.

Another study investigating the link between the results of milk cultures and breastfeeding pain also reported that candida was found in a significantly greater proportion of women who were suffering from sharp, shooting breast pain: 6/20 (30%) of the women with pain tested positive for it, but only 6/78 (5%) of the no pain group4. This study also tested for levels of common bacteria, and found they did not differ significantly between the two groups.

Evidence that symptoms associated with thrush may be caused by something else

There are other experiments, however, which indicate that bacteria – rather than fungi – may be the culprit in some occurrences of breastfeeding pain. A study comparing culture results of 20 women with deep, stabbing pain, 20 with superficial nipple pain and 20 controls with no pain found an association between candida and superficial pain, and bacteria and deep pain: candida was found on the nipples of 1 of the control group, 12 of the superficial pain group and 10 of the deep pain group; and in the milk of 1 of the control group, 10 of the superficial pain group and 5 of the deep pain group5. By contrast, pathogenic bacteria were detected on the nipples of 4 of the control group, 11 of the superficial pain group and 19 of the deep pain group, and in the milk of 6 of the control group, 8 of the superficial pain group and 14 of the deep pain group.

Support for the idea that thrush does not underlie all breastfeeding pain is also provided by a recent study that compared levels of candida in the milk of 18 healthy breastfeeding mothers and 16 with thrush symptoms (sore, inflamed or traumatized nipples, intense stabbing or burning pain and painful breastfeeding that had not received any other diagnosis)6. The investigators were very careful to avoid contamination of the sample: nipples were thoroughly washed, and breasts were pumped for 12 minutes before any milk was collected. No evidence of candida was found in any of the samples, leading the authors to suggest that it does not infect milk ducts, and is unlikely to be the cause of the symptoms associated with thrush. They also go a step further, and suggest that positive nipple cultures cannot be trusted, as they may be contaminated by the baby’s saliva, which often contains candida. They conclude that, ‘candida infection on the mother’s skin remains a possibility, but it seems unlikely.’

This interpretation of the results seems fairly extreme. In previous studies, candida has been found to colonize milk (but not nipples)2 so the possibility that thrush may infect milk ducts cannot be ruled out. It is also not really appropriate to draw conclusions from the data about candida infection of the nipple, or the role of bacteria in breast pain, as neither of these things was actually examined. There is some evidence that bacteria may underlie certain instances of breast pain – it has been found at higher concentrations than candida in the milk of women suffering from deep pain5 – but this result conflicts with another reporting higher levels of candida in women suffering from a similar complaint4.

It is not only the role of bacteria that is hazy, however: despite the association between candida and symptoms reported in some studies, this link is far from concrete. Not every woman with the symptoms of thrush tests positive for candida, and some who are colonized by it never report symptoms. If you also consider that cultures themselves can be easily contaminated and may therefore be unreliable, the picture gets even more complicated.

Treating the symptoms of thrush

What does all this mean for breastfeeding women who appear to be suffering from thrush? Some researchers take the view that as the relationship isn’t sufficiently proven, women should not be treated with antifungal medication, or should receive it only as part of a controlled trial7. Others take a more pragmatic view, and suggest that such medication can actually have a useful diagnostic value: if the symptoms clear up after using an antifungal, then this ‘confirms’* that the symptoms were caused by candida8. This is far from an ideal solution (using such medications unnecessarily is expensive and increases the chances of fungi developing resistance to them), but it may be preferable to leaving women to suffer with very painful symptoms when there is chance they could be cured. Women who exhibit the symptoms of thrush when breastfeeding are at a very high risk of giving up3, so if there’s a medication that could stop this from happening, it may not be a bad idea to use it.

  1. Breastfeed Med. 2009 Jun;4(2):55.
  2. J Hum Lact. 2004 Aug;20(3):288-95.
  3. J Obstet Gynecol Neonatal Nurs. 2005 Jan-Feb;34(1):37-45.
  4. Am J Obstet Gynecol. 2007 Oct;197(4):424.e1-4.
  5. Gynecol Obstet Invest. 1998 Aug;46(2):73-4.
  6. Breastfeed Med. 2009 Jun;4(2):57-61
  7. Breast. 2002 Feb;11(1):88-90
  8. J Hum Lact. 1999 Dec;15(4):281-8.

*Of course, this doesn’t really confirm that a mother was suffering from thrush, as the alleviation of her symptoms may have been coincidental.

Should ‘moist wound healing’ principles be applied to cracked nipples?

pot-of-vaselineMaintaining a slightly damp, rather than dry, environment under a dressing has been shown in many studies to help wounds heal faster. Moisture prevents a scab from forming, which allows new epithelium cells to move across the surface of the wound more quickly, and reduces the time it takes it to close1.

As the technique appears to improve the healing rates of a range of skin lesions2, it has been suggested that its benefits may extend to cracked nipples3, and there are now several off-the-shelf creams and dressings that claim to maintain a moist environment, and thus help the healing process. The inference is not, at first glance, unreasonable – if moisture helps skin to regenerate more quickly, then it may well help injured nipples to recover too. It is important to remember, however, that nipples are subject to a unique set of circumstances when a mother is breastfeeding, so it is also quite possible that the application of the technique might not be appropriate. Is there any scientific evidence that applying moist wound healing principles can aid the recovery of cracked or injured nipples?

In a study comparing dressings made from hydrogel with lanolin (both classified by the Breastfeeding Network as having ‘moist wound healing’ properties)4, 106 mothers were allocated at random to one of two groups: the first was given hydrogel dressings to use between feeds; the second was given lanolin cream. Mothers started using the treatments within 24 hours of giving birth, and their effectiveness was assessed via telephone interviews 3, 4 or 5, 7, 10 and 12 days later. The researchers found mothers reported significantly lower pain scores (a difference of just under 1 point, on a scale of 1-5) in the hydrogel group on days 10 and 12.

There were a couple of problems with this study (actually, there were several, but I’ll limit it to the major ones). Firstly, there was no baseline group of mothers not applying anything to their nipples, so it is not possible to say whether either treatment was better than simply leaving nipples alone. A second issue is that the people conducting the interview were aware, when they spoke to the participants, which treatment they were receiving. The researchers claim that to have conducted the study blind would have been ‘impossible’, an unsubstantiated and somewhat odd statement, as it would appear to be completely possible to interview a mother over the phone without knowing what she had on her nipples. Knowledge of the treatment group in this type of study is a problem if there is any chance that the researcher may have a bias towards a particular treatment, as they may subconsciously influence the patients’ responses. It may be worth mentioning at this point that the research was funded by Tyco, the manufacturers of the dressings.

These criticisms are, however, a digression. The main thing to note about this research is that it did not test whether the dressings actually helped wounds to heal. Although moist wound healing is touted in the introduction as the ‘science bit’ justifying the use of the dressings, it is not mentioned anywhere in the procedure or the results.

A hospital-funded study comparing hydrogel and lanolin – this time documenting the impact that the treatments had on bleeding and cracked nipples – did not find the dressings to be quite so effective5. Researchers who were blind to the treatment group rated nipples as healing significantly better when women used lanolin with breast shells, rather than hydrogel dressings. Self-reported measures of pain were also significantly lower in the lanolin group. A final point worth mentioning is that the study was halted early, due to a third of the 21 women in the hydrogel dressing group developing an infection.

Although this study compared two treatments, it is again compromised by the lack of a proper control group. We can see that lanolin appears to result in improved healing and lower pain scores when it is compared with hydrogel, but we still do not have any evidence that moist wound healing techniques are useful for treating injured nipples when breastfeeding – to ascertain this requires a control group where mothers keep their nipples dry.

So far, there appear to be only two studies that have looked at this issue. An experiment published in 1995 examined whether using a polyethylene adhesive dressing had any effect on the development of nipple redness, fissures and pain6. 50 mothers took part in the study, using a dressing on one nipple, and leaving the other untreated. Although the mothers reported less pain when feeding with the treated nipples, the researchers caution that this may simply have been because of the ‘Hawthorne Effect’ (the mere fact there is an intervention is enough to cause an improvement.) The dressings made no difference to the development or healing of fissures or redness, as reported by observers blind to the treatment group. 16% of the participants dropped out due to finding the dressings uncomfortable, and 66% said they found it uncomfortable to remove them – something they had to do before every feed.

A more recent study looked specifically at the effect of lanolin on the healing of nipple fissures7. 225 women, all with fissures, were randomly allocated to one of three groups: in the first group mothers applied lanolin 3 times a day; in the second they applied breast milk after each feed; in the third they applied nothing. The appearance of their nipples was assessed 3, 5, 7 and 10 days after starting the treatment by researchers who did not know which group the mothers were assigned to. There was no significant difference in healing time between the breast milk and no-treatment groups. The nipples of the women using lanolin, however, took significantly longer to heal (45% of this group took longer than 7 days, as opposed to 32% of the milk group, and 25% of the no-treatment group).

There is another area of research, which does not examine the use of moist wound healing directly, but is still relevant to the debate. Broken skin makes nipples vulnerable to infection8, which may mean there is an additional problem with keeping nipples damp, rather than dry: organisms like thrush are known to thrive in warm, moist environments9.

Given the possible risk of infection, and the evidence that maintaining a moist environment around cracked nipples may potentially delay the healing process, it seems to unwise to recommend the application of the products described above to mothers with cracked or fissured nipples. In spite of this, they continue to be promoted by both commercial companies and health professionals on scientific grounds. Until evidence that genuinely supports its use is found, presenting moist wound healing to mothers as a clinically tested treatment is at best misguided, and at worst dishonest.

  1. Nature. 1962 Jan 20;193:293-4.
  2. Br J Nurs. 2008 Aug 14-Sep 10;17(15):S4, S6, S8 passim.
  3. J Hum Lact. 1997 Dec;13(4):313-8.
  4. J Obstet Gynecol Neonatal Nurs. 2003 Jul-Aug;32(4):486-94.
  5. Arch Pediatr Adolesc Med. 1998 Nov;152(11):1077-82.
  6. Nurs Res. 1995 Nov-Dec;44(6):347-51
  7. Saudi Med J. 2005 Aug;26(8):1231-4
  8. J Hum Lact. 1991 Dec;7(4):177-81.
  9. Hum Lact. 1999 Dec;15(4):281-8.

Could persistent nipple pain be caused by the strength of your baby’s suck?

barracudaUp to 90% of women experience nipple pain or soreness in the initial stage of breastfeeding, with the pain peaking in the first week, then gradually subsiding1. But what if, after 6 weeks, breastfeeding still hurts? You have been observed by what seems like hundreds of lactation professionals, and everything looks fine: your baby is latching on properly and you don’t have an infection. It simply feels to you like she is just a very ‘enthusiastic’ feeder, demonstrated by her toe-curlingly strong suck. Surely that couldn’t be the problem… could it?

Very little research has investigated the causes of chronic pain during breastfeeding, but one interesting study in this area has found a link between nipple pain and a baby’s ‘intra-oral vacuum’, or suck2. The study looked at two groups of women: 30 mothers who were experiencing persistent, unexplained nipple pain (without injury), despite help from lactation specialists; and a control group of 30 mothers with no problems breastfeeding. The vacuum produced by each baby whilst on the breast was measured using a small tube taped to the nipple and attached to a pressure sensor. The amount of milk the babies consumed was also measured, by weighing the babies before and after the feed.

The results were startling. The babies of the mothers who experienced pain when feeding exerted a vacuum when they were ‘actively’ sucking (taking in milk) that was more than 50% higher than the babies in the control group. In between these periods, when they were resting, the vacuum produced by the babies in the pain group was more than twice as high. Unfortunately, a stronger suck did not translate into more milk: babies in the pain group consumed on average 42% less milk, despite feeding for a similar length of time.

The cause of the lower milk intake wasn’t clear. There is a possibility that it was due to chance, or the experimental set-up, although the amount consumed in the control group babies matched that recorded in previous research, making this less likely. As pain can interfere with the let-down reflex, it’s possible that the simple fact that it hurt was enough to stop the milk from flowing properly3. This may in turn have affected milk production, as the amount of milk a baby consumes determines the rate at which it is produced4. It is important to point out, however, that all the babies in the study were gaining weight sufficiently, so the lower milk consumption documented in this single feed did not appear to translate into a more general nutrition problem.

The reason for the higher vacuum is also elusive. It may in some way be the effect rather than the cause of the restriction in milk flow, although this is purely speculative, and how and why this would happen isn’t clear. It’s also possible that the babies in the study may have been experiencing some other feeding difficulty that they compensated for with a stronger suck, although this had not been identified by any of the health professionals who had come into contact with them.

The study data indicate quite clearly that the women suffering from persistent, unexplained nipple pain had babies who exerted a significantly higher intra-oral vacuum on the breast when feeding. Although the data can’t prove the stronger suck caused the pain, it’s likely the two are related. Could this be the reason why for some women, breastfeeding never really seems to become comfortable? If you’re on the receiving end of high suction, then it’s easy to see how you could feel ambivalent about these results. On the one hand, it may be a relief to know that breastfeeding can be painful as a result of the way that your baby suckles, and not because of something that you are doing wrong. On the other hand, the prognosis may be a little disheartening, as it isn’t immediately clear how you solve a problem like this.

At present, such a diagnosis is unlikely, as intra-oral vacuum is rarely tested. The results of this study, however, suggest that in situations where chronic nipple pain has no obvious cause, that it probably should be (the authors certainly think so). Discomfort when breastfeeding is a difficult and stressful situation to deal with, and only with more research in this area can a cause (and hopefully a treatment) be identified. In the meantime, it seems that affected mothers need to carry on gritting their teeth, and perhaps reach for the pain killers…

  1. Acta Paediatr. 2008 Sep;97(9):1205-9.
  2. J Obstet Gynecol Neonatal Nurs. 2005 Jul-Aug;34(4):428-37.
  3. J Pediatr. 1948 Dec;33(6):698-704.
  4. J Exp Physiol. 1996 Sep;81(5):861-75.

Peppermint might help prevent early breastfeeding nipple problems

peppermintThere are many substances said to prevent or relieve nipple pain and damage during the early days of breastfeeding, including lanolin, expressed breast milk and water compresses. Unfortunately, none as yet have been found to offer any real improvement over leaving nipples untreated1. Given the prevalence of the problem, however, the search for a preparation that can make early breastfeeding more comfortable continues.

Recent research reported in the International Breastfeeding Journal and Medical Science Monitor finally seems to offer a ray of hope. It suggests that peppermint, in the form of a gel or ointment, could play a role in preventing nipple soreness and injury from appearing in the first place. A team at the Alzahra Teaching Hospital in Iran conducted two studies examining whether peppermint could prevent nipple problems caused by breastfeeding, after noticing its use by women in the Azarbaijan Province, North West of Iran. As peppermint has antibacterial properties and can increase tissue flexibility2 it does have the potential to prevent this kind of injury occurring, but it has not before been properly evaluated in a clinical setting.

In the first study, 196 women were randomly allocated to either the experimental group, where they were asked to apply peppermint water after each feed, or the control group, where they applied expressed breast milk3. Mothers who applied the peppermint water reported significantly less pain on breastfeeding, and had significantly fewer nipple cracks (9% in the peppermint group and 28% in the milk group) than the other mothers. Cracks that occurred in the peppermint group were also less severe than those in the milk group.

The second study evaluated the effectiveness of a peppermint gel in a double blind study4. 216 women were randomly allocated to one of three groups: the first used peppermint gel after each feed; the second used lanolin; and the third used a placebo gel. The peppermint gel was shown to be more effective than both lanolin and the placebo gel at preventing nipple cracks. Women in this group were also more likely to be exclusively breastfeeding at 6 weeks, possibly because they had suffered less discomfort.

Both these studies were large and well designed, and as such offer reasonable evidence that peppermint may indeed help to prevent the nipple pain and trauma that can occur when women start to breastfeed. These results alone, however, do not constitute conclusive proof that peppermint is a panacea for nipple problems. The main issue is that both experiments were carried out by the same research group, in a part of the world where peppermint is regularly used as a nipple treatment. In the first study women knew they were applying peppermint water, and this may have affected their perceived levels of pain. These mothers were also found to nurse their babies more frequently and for longer periods than those using milk. The authors suggest this may be due to the lower pain levels in this group, but the possibility that the more frequent feeding somehow reduced pain and trauma cannot be ruled out.

In the second study, both the mothers themselves and the researchers classifying the severity of nipple cracks were unaware which type of gel they were applying, reducing the chance that the results were due to a placebo effect. In this experiment, however, there was no true baseline (where nipples were left untreated) against which to compare the peppermint gel. It was better at preventing cracks than the placebo gel (which was the same preparation, just without the peppermint), but we can’t be sure that the gel didn’t make it worse, and the peppermint simply helped to ease the problems caused by the gel.

Despite these shortcomings, this research does provide a strong indication that peppermint may have the potential to protect mothers against nipple soreness and injury. Peppermint has medicinal qualities that suggest it might be helpful in this context, and it is likely to be a reasonably safe and practical treatment, as it is not harmful to babies when consumed in small quantities. Whether future research can replicate these results is yet unknown, but if it can, then an effective preventative measure for nipple problems may finally be on the horizon.

  1. J Obstet Gynecol Neonatal Nurs. 2005 Jul-Aug;34(4):428-37.
  2. Fitoterapia. 2006 Jun;77(4):279-85.
  3. Int Breastfeed J. 2007 Apr 19;2:7
  4. Med Sci Monit. 2007 Sep;13(9):CR406-411

Breast shells: preserving your modesty

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.
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