When available studies are limited, expert opinions count

As a strong believer in evidence-based medicine, the lack of the highest quality of studies and sometimes of sound scientific interpretation in articles about Asherman’s syndrome is disappointing. It can be difficult to accurately assess information on AS from different sources when primary studies may be deficient in study design, use outdated techniques of diagnosis or treatment,  have small sample sizes, are carried out retrospectively, randomization/allocation concealment are absent and when comparisons between primary studies is impossible due to differences in methods of treatment. Unfortunately some of these limitations are difficult, if not impossible to overcome. However, there is still room for improvement in studies about AS. There is also a lot we can learn about AS by correctly interpreting data that is already available, and by taking note of the knowledge acquired from specialists with extensive expertise on the topic. To be knowledgible about AS requires more than having the letters MD behind your name, learning about AS through a 10 minute lecture at University and skimming through a few papers on it. To be an expert requires decades of experience with diagnosing and treating it and the ability to think scientifically (objectively), something doctors are not actually taught routinely which is only really pertinent to doctors that are involved in research.

Dr Charles March of California Fertility Partners is a respected authority on Asherman’s syndrome. He is board certified in Obstetrics and Gynecology and fellowship trained in Reproductive Endocrinology and Infertility and was a Professor at University of Southern California. Not only is he a great surgeon who is popular with patients, but I believe he is currently the doctor with the most knowledge about Asherman’s syndrome. This is probably due to the fact that he has over 30 years of experience in dealing with patients that have Asherman’s syndrome and that he is additionally a fertility specialist and obstetrician which enables him to clearly see the causes and repercussions of the condition. He also has a particular interest in the condition and clearly enjoys talking and educating others about it.

His most recent review article,‘Management of Asherman’s syndrome’, appeared in Reproductive Biomedicine Online this year. His articles show that he is a wealth of information on all aspects of AS. Anyone can write a narrative review by consolidating previous data and supporting their arguments with cherry-picked information they have read, sometimes from old or inaccurate sources, but only those who have strong critical appraisal skills and the know-how that comes from decades of experience can offer so much valuable insight and advice on a topic. My next blog will focus on the relevant discussions and kernels of wisdom found in Dr March’s review on Asherman’s syndrome.

Indispensable technique becomes disposable to boost its use

A new single-use disposable hysteroscope (http://hcp.obgyn.net/conference-insider/aagl2011/content/article/1760982/1976908 and http://hcp.obgyn.net/conference-insider/aagl2011/content/article/1760982/1980724) is being investigated by Dr Paul Indman in hopes that, once FDA-approved for commercial use, it will encourage more gynecologists to carry out diagnostic hysteroscopy in an office setting. Dr Indman believes that it is just as important for a gynaecologist to be able to look inside the uterus as it is for an ear doctor to look inside the ear. While nothing seems more evident, fewer than 10% of Obgyns in the US are trained to perform in-office hysteroscopy. This is due to a number of factors including the lengthy preparation and costs of setting up traditional hysteroscopy. Conventional ones are large and cumbersome, and need to be sterilised before each use. Besides the actual hysteroscope, a video camera, monitor and lighting are necessary to perform the procedure. The new hysteroscope is hand-held with a plastic disposable hysteroscope and a reusable handle that has a monitor, light source and a high resolution camera the size of a pin-head incorporated into it. Currently, plastic disposable curettes are used for D&C, so there is no basis for the concern that this will increase pollution to the environment. Hopefully it will be available in the near future and more gynaecologists and fertility specialists will take an interest in using this less-invasive technology to improve diagnosis of women’s health problems. Note: There is another similar device that is available for ~ 300 USD: http://medgadget.com/2007/01/femsuites_femey.html

(Disclaimer:  It is up to medical professionals who are trained in hysteroscopy to assess the performance of these products. I am not in a position to endorse them).

Hysteroscopy is gold-standard method for the evaluation of the uterine cavity to diagnose conditions such as intrauterine adhesions, endometrial polyps and fibroids and structural malformations such as septate uterus. Operative hysteroscopy is used for treating the diagnosed condition where microscissors or other instruments are used for tissue dissection. A resectoscope is a hysteroscope which is equipped with loop that uses electrical energy for cutting, although the loop can be used without thermal energy as a mechanical cutting tool.

Operative hysteroscopy is also used by some gynecologists to remove retained products of conception in select patients and/or situations. It may raise eyebrows among some medicaI professionals who have been trained to rely on blind curettage (D&C) for a wide range of diagnostic and therapeutic indications, but there should be no reason why it is not routinely used in Gynecology, including for ERPC when expectant or medical management fail to completely empty the uterus after a miscarriage, instead of blind curettage. There are a number of publications describing hysteroscopic curettage (1-7) for removing RPOC. Blind curettage is the most common cause of intrauterine adhesions (Asherman’s syndrome), which leads to infertility necessitating corrective surgery. The lack of Obgyns suitably trained in hysteroscopy is another reason why hysteroscopy has not replaced the D&C. Unfortunately, the use of hysteroscopy in Gynecology is even declining from the time it was first invented in the 1980s. Hysteroscopy is the logical progression from blind scraping invented over a century ago. It’s hard to believe that over a century later this comparatively rudimentary technique for women is still being used. Minimally invasive techniques are routinely used in Urology (e.g. in-office cytoscopy). Women also need to empower themselves and support more precise and safer methods by choosing hysteroscopy over blind curettage. Most gynaecologists perform blind curettage without giving a second thought to any long term risks involved. They may not be aware of the future problems it has caused their patients unless the patient specifically contacts them to tell them.  

Finally, this article by Dr Keith Isaacson(8) is not new, but it outlines the uses of hysteroscopy, compares office and hospital hysteroscopy and dispels the common misconceptions about it that are hindering its widespread use, such as poor reimbursements and a difficult learning curve. http://www.obpmedical.com/v/vspfiles/assets/images/office%20hysteroscopy%20-%20a%20valuable%20but%20under-%20utilized%20technique.pdf

REFERENCES

1. Nicopoullos JDM, Treharne A, Raza A and Richardson R. The use of a hysteroscopic resectoscope for repeat evacuation of retained products of conception procedures: a case series. Gynecological Surgery. 2010; 7(2):163-6. Abstract http://www.springerlink.com/content/384125gp81055401/  
2. M.H. Emanuel, F.W. Jansen and D. Schoot The Hysteroscopic Morcellator, an Effective Technique for the Removal of Residual Trophoblastic Tissue Journal of Minimally Invasive Gynecology Volume 16, Issue 6, Supplement 1, 2009, Page S85. 
3. Faivre E, Deffieux X, Mrazguia C, Gervaise A, Chauveaud-Lambling A, Frydman R, Fernandez H. Hysteroscopic management of residual trophoblastic tissue and reproductive outcome: a pilot study. J Minim Invasive Gynecol. 2009 Jul-Aug;16(4):487-90. Abstract www.ncbi.nlm.nih.gov/pubmed/19573826
4. T. Dankert & M. Vleugels. Hysteroscopic resection of retained placental tissue:a feasibility study Gynecol Surg . 2008; 5:121–124. Free article www.springerlink.com/index/w4021j484l211057.pdf  
5. F. Leone, T. Bignardi, C. Marciante, E. Bertazzoli, P. Mustoni, E. Ferrazzi and L. DSC 74: Hysteroscopy for Selective Removal of Residual Trophoblastic Tissue. Journal of Minimally Invasive Gynecology 2005;12(5), Supplement 1: 30-1.
6. Cohen SB, Kalter-Ferber A, Weisz BS, Zalel Y, Seidman DS, Mashiach S, Lidor AL, Zolti M and Goldenberg M. Hysteroscopy May Be the Method of Choice for Management of Residual Trophoblastic Tissue. The Journal of the American Association of Gynecologic Laparoscopists 2001;8(2):199-202. Abstract
7. Goldenberg, M, Schiff E, Achiron, R. Lipitz, S. Mashiach, S. Managing residual trophoblastic tissue. Hysteroscopy for directing curettage. J Reprod Med. 1997;42(1)26-8. Abstract www.ncbi.nlm.nih.gov/pubmed/9018641
8. Isaacson K. Office hysteroscopy: a valuable but under-utilized technique.Current Opinion in Obstetrics and Gynecology 2002, 14:381-385. Free article http://www.obpmedical.com/v/vspfiles/assets/images/office%20hysteroscopy%20-%20a%20valuable%20but%20under-%20utilized%20technique.pdf

Endometrial injury subfertility and superfertility: a decidual link.

Miscarriages occur in approximately 20% of pregnancies. Recurrent pregnancy loss (RPL), affects 1-2% of couples and is defined as three or more consecutive miscarriages. Broadly speaking, the most common cause is chromosomal abnormalities of the embryo. Other causes of RPL include immunological factors (e.g. Lupus), blood clotting disorders a.k.a. thrombophilias (e.g. antiphospholipid syndrome) and uterine factors which are less well understood. The authors of the review article, The molecular basis of recurrent pregnancy loss: impaired natural embryo selection, examine uterine factor infertility and its relation to recurrent miscarriage. 

Researchers have noted that many women with recurrent and consecutive miscarriages, have unusually high pregnancy rates, conceiving within an average of 3 months or less. These women are dubbed ‘superfertile’, though the concept of superfertility in humans is anecdotal and not based on clinical diagnostic testing. Three percent of the population is estimated to be superfertile, compared to 18% estimated to be subfertile (Tietz, 1950; Evers, 2002). It has already been hypothesized that recurrent miscarriage is a consequence of impaired natural embryo selection, in other words, the inability of the uterus to filter out poor quality embryos destined to miscarry (Quenby, 2002). In their review, Teklenburg et al examine the biological plausibility of superfertility as a pathological entity leading to apparent infertility. They use results from their own studies and others to lead to the hypothesis that cyclic changes in the endometrium ensure normal implantation, and that a dysfunctional endometrium associated with superfertility will lead to perturbations in the endometrial decidual response, delayed implantation and poor embryo selection resulting in defective placental formation and miscarriage, regardless of embryo karyotype. This would explain why karyotype analysis of miscarried embryos from superfertile women reveal both chromosomally normal and abnormal embryos. 

To arrive at this theory, they examined the implantation window of the embryo and its coordination with endometrial development. There is clinical evidence that an unresponsive endometrium during the window of implantation is a cause of subfertility. Thus, one would expect that persistent endometrial receptivity will result in higher implantation rates but would also include embryos of poor quality (i.e. superfertility). Central to the process of implantation is decidualization, which occurs about 10 days after ovulation regardless of pregnancy status. This is the process by which endometrial stromal cells differentiate into decidual cells giving the endometrium properties necessary for placenta formation. Inadequate decidualization leads to miscarriage or obstetric complications such as preterm birth. Underlying implantation is a complex molecular cross-talk between the embryo and the endometrium, a process triggered by the hormone progesterone which is responsible for maintaining the endometrium’s integrity during a viable pregnancy. Several types of molecular regulators including growth hormones, transcription factors, and cytokines are needed to mediate the implantation process. The window during which the endometrium is receptive to embryo implantation occurs approximately 6 days after ovulation, lasting for around 5 days. The proposals that miscarriages may be caused by impaired embryo selection or conception outside of the normal implantation window are not new. There is already some evidence from studies to support that impaired embryo selection underlying a short time to pregnancy is a cause of sporadic miscarriages.

Cyclic decidualization in the absence of pregnancy results in menstruation. Researchers have tried to explain from an evolutionary standpoint, why a process which results in the ‘punitive’ occurrence of repeated menstruation arose. One possible explanation is uterine preconditioning which protects the uterine tissues from hyperinflammation and oxidative stress resulting from deep trophoblast invasion during pregnancy.  Another possible explanation put forth by Teklenburg et al in this review is embryo natural selection.  In human co-culture studies, their group recently observed that blastocysts were unable to trigger a maternal response in endometrial stromal cells which had not been decidualized, yet they were able to in decidualizing cells. This led them to hypoethsize that an important function of decidualization is to provide endometrial stromal cells the ability to act as biosensors of embryo quality (Teklenburg et al, 2010a). Therefore the failure of the endometrial stromal cells to undergo an appropriate decidualization would lead not only to late implantation of poorer quality embryos but also to early placental failure regardless of embryonic karyotype. Thus, the ability of the decidualized endometrium to terminate the window of implantation could be just as important for a viable pregnancy as its ability to become receptive.

They propose that this instrinsic failure of endometrial stromal cells to mount an appropriate decidual response is due to a reversible programming of endometrial cells, most likely epigenetic changes such as DNA methylation. 

Implications for Asherman's syndrome?

This hypothesis can potentially explain many causes of uterine factor infertility as well as their current treatments. For example, inflammatory signals are important epigenetic modifiers (Backdahl et al, 2009). Although the review does not mention Asherman's syndrome, it could be speculated that tissue injury from D&Cs resulting in inflammation can lead to epigenetic modification that underlies recurrent miscarriage. Of course this may happen even if the injury does not lead to intrauterine adhesion formation. The persistence of epigenetic modification from the initial trauma could also explain why even after corrective surgery women who had Asherman's syndrome may continue to experience miscarriage or perhaps even become ‘superfertile’ from a defective decidual response. Although superfertility in Asherman’s syndrome has not been previously reported to my knowledge, it is biologically plausible if the theory about epigenetic modification subsequent to endometrial injury is correct. It could also explain why women may become infertile even in the presence of few intrauterine adhesions. Conversely, local injury using endometrial biopsy has been used to improve pregnancy rates in subfertile women, lending support to the theory that tissue injury can modify the decidual response (for the better in this case). How injury can increase fertility in some cases or reduce it in others is unclear, but would probably be related to the extent and location of the injury and baseline fertility characteristics specific to the woman. An interesting study would be to compare decidualization in women with and without Asherman’s syndrome through the expression of uterine proteins and factors involved in decidualization. The potential link between endometrial injury and superfertility may also explain the obstetric complications encountered in women with a history of Asherman’s syndrome such as placenta accreta and percreta, intrauterine growth restriction and preterm birth since these are all related to impaired placental function. 

If the above hypothesis is correct, the bad news is that prenatal genetic diagnosis (PGD) and comparative genomic hybridization (CGH) would not be effective treatments for recurrent miscarriage since even chromosomally normal embryos would abort in the presence of a defective decidual response. Variations in the prevalence of superfertile versus subfertile or infertile patients in different studies could explain the conflicting  efficacies reported for these techniques. There is at least some hope for women with recurrent miscarriage; the authors point out that even after 3 consecutive miscarriages many women with RPL go on to have a successful pregnancy. (Rai and Regan, 2006). The authors also noted that many of the drugs used in the management of RPL (progesterone, DHEA, glucocorticoids and heparin) directly modulate the decidual response and that the timing of their administration could be the critical factor in their outcome.

A better understanding of the endometrium and its decidual response may hold the key to preventing recurrent miscarriage and future obstetric complications. Perhaps the confirmation of an association between endometrial injury, defective decidualization and recurrent pregnancy loss would further support the need to switch to non-invasive and minimally invasive gynecological and obstetric treatments. 

REFERENCES  

Backdahl L, Bushell A, Beck S. Inflammatory signalling as mediator of epigenetic modulation in tissue-specific chronic inflammation. Int J Biochem Cell Biol 2009;41:176 – 184.

Evers JL. Female subfertility. Lancet 2002;360:151 – 159.

Quenby S, Vince G, Farquharson R, Aplin J. Recurrent miscarriage: a defect in nature’s quality control? Hum Reprod 2002;17:1959 – 1963.

Rai R, Regan L. Recurrent miscarriage. Lancet 2006;368:601 – 611.

a. Teklenburg G, Salker M, Molokhia M, Lavery S, Trew G, Aojanepong T, Mardon HJ, Lokugamage AU, Rai R, Landles C et al. Natural selection of human embryos: decidualizing endometrial stromal cells serve as
sensors of embryo quality upon implantation. PLoS ONE 2010;5:e10258.

Teklenburg G, Salker M, Heijnen C, Macklon NS, Brosens JJ. The Molecular basis of recurrent pregnancy loss: impaired natural embryo selection. Mol Human Reprod. 2010;16(12): 886-895.

Tietze C, Guttmacher AF, Rubin S. Time required for conception in 1727 planned pregnancies. Fertil Steril 1950;1:338– 346.

Articles on Asherman's syndrome: Reproductive outcomes and Obstetric complications

The final section on references to peer-reviewed publications on Asherman's syndrome have been uploaded under pages (please see relevant tab above or click here). It includes case reports, studies and reviews of reproductive outcomes (pregnancy rates, live birth rates), obstetric complications in women with a past history of Asherman's syndrome (e.g. placenta accreta, IUGR etc.), as well as in women who have untreated intrauterine adhesions at the time of pregnancy. I also included some articles on fertility complications in women who have had Asherman's syndrome, such as thin endometrium. I will continue updating all pages with new articles when they are published. I also intend to add other articles such as those on stem cells, uterine transplantation, hysteroscopy, treatment of thin endometrium, and general articles on misoprostol and the risks of D&C, so stay tuned.

A genetic predisposition: from speculation to opinion to 'fact' without any data (Part II)

In my last blog post I presented the ‘evidence’ (or lack thereof) on which the theory of a genetic/constitutional predisposition for Asherman's syndrome was based. To recap the gist of these observations which pass for proof:

a) some women develop a severe form of IUA after undergoing the ‘same’ traumatic procedures as others who do not acquire AS, and 

b) some women respond more ‘favourably’ to treatment than others who suffer from recurrent adhesions. 

Before deconstructing these observations, the most obvious argument against a genetic basis is the lack of familial clustering of the ‘pathology’. Assuming a polygenic mode of inheritance (as opposed to a Mendelian one) it would be expected that those with a first degree relative with Asherman’s syndrome would have a higher risk of  developing AS than those without a close relative who has the condition. I have yet to read a study of identical twins with Asherman’s syndrome, let alone any study showing the sisters or daughters of patients having a higher risk. In over a century since its first report, there is no evidence of familial clustering to lend support to this theory. Nor is there any evidence that women with scarring defects (eg. keloids) or connective tissue disorders (Marfan’s syndrome, Ehlers-Danlos syndrome) are more prone to AS as one might expect. 

How can trauma be quantified when surgery is blind?

As for the ‘evidence’ above, with regards to a), what proof is there that the women who develop severe IUA actually underwent the exact same trauma as those who did not acquire it? This is a an unfounded statement given differences in doctor’s skill, technique and more importantly, the mis- or under-diagnosis of AS and the blind nature of D&Cs- the number one cause of AS. The problem with bind surgery is that one relies on guess work and instinct to not scrape too deeply. ‘Too deeply’ can be one millimeter too much. How is it possible to detect this difference when not even an ultrasound is used during the procedure? Even with visualization it is not possible to tell where the functional endometrium ends and the basal endometrium begins. However, techniques which utilize visualization for intrauterine surgery (i.e. hysteroscopy) are inherently less risky with regards to instrumental injury because they allow the surgeon to only scrape/dissect/remove parts of the endometrium which need to be treated thus sparing underlying and adjacent tissue from potential injury. Furthermore, each woman has a different anatomy, and different location of retained products of conception. Some have retroverted uteri, others have Mullerian malformations, and the shape, widths and lengths of uteri vary enough between women to be a significant factor with regards to acquiring an injury during a blind procedure. A D&C consists of blindly scraping away the top layer of the endometrium (the functional layer) which can vary in thickness between women but is often not thicker than a few millimeters in most parts. It is simply impossible for a clinician or midwife to know whether they have scraped into the basal endometrium, particularly when no visual guidance is used. 

In summary, the above argument is akin to saying that not all smokers develop lung cancer therefore lung cancer is not caused by cigarettes. Why not theorize that those who develop lung cancer have a genetic predisposition instead? (Note: this comment was intended to highlight the absurdity of believing that cigarette smoking does not cause lung cancer, and hence the absurdity of believing that the fact that all women who have D&Cs do not acquire Asherman's syndrome proves that the condition is not caused by D&Cs but is instead genetic. I later learned that the famous statistician RA Fisher actually theorized half a century ago that people who are genetically predisposed to lung cancer are also genetically predisposed to becoming smokers. Of course this theory was refuted by a study of monozygotic twins versus dizygotic twins who were discordant for cigarette smoking, and it turns out,  lung cancer risk. This example points out how easily theories can be taken seriously just because an expert, or in this case, a genius put it forth, and that experts too have biases which affect their views (he smoked and was a consultant for the tobacco industry!). These theories, will not hold up against evidence from well-designed studies, but until these are done, they impede medical progress).

Recurrence depends on initial severity and treatment methods

With respect to the second part of the argument, the fact that some women respond more ‘favourably’ to treatment than others who suffer from recurrent adhesions can be rationally explained in other ways.

Firstly, it is not surprising that some women need more than one hysteroscopic adhesiolysis surgeries than others, depending on severity. This has been known for many years and reported in the literature. The more damage incurred on the endometrium, the higher the rate of IUA recurrence, and the more surgeries needed for correction, although at some point, damage is too great to allow for endometrial regeneration resulting in recurrent adhesions or fibrotic endometrium.

Another important point to consider is that hysteroscopy was not used for diagnosis or treatment when the observation about treatment outcomes was made. Asherman’s syndrome was still ‘treated’ with blind D&C, the same procedure which is responsible for most cases of AS. This would understandably result in inconsistent outcomes. The absence of accurate diagnosis (and hence classification) in those days also distorted the correlation between severity and outcome. A patient with seemingly severe AS presenting with total amenorrhea may ‘inexplicably’ have had a better outcome after surgery than someone with supposedly less severe AS who had some menstrual flow. We now know that amenorrhea is not always due to severe and widespread adhesions. It can be due to cervical adhesions alone. As the rest of the uterus may be intact in such cases, the reproductive prognosis is better than a patient who has deep adhesions in part of her uterus but no outflow obstruction (and thus has menstrual bleeding, albeit reduced flow). 

With regards to treatment, estrogen therapy was not carried out as part of post surgical therapy in the past. It is generally accepted that estrogen supplementation plays an important role in the prevention of adhesion recurrence following surgery/adhesioloysis by stimulating endometrial regeneration. Thus in the absence of hysteroscopic adhesiolysis, uterine stents and estrogen therapy, more severe cases were less treatable than they are today. 

It is well known that the functional endometrium is regenerated from the underlying basal endometrial layer. As a simple analogy, imagine the lining of the uterus as a lawn. The grass seeds would be the stem cells from which the grass grew with the addition of water (i.e. estrogen). The functional layer would be the grass, and the roots would be the basal endometrium. If someone came along to trim the lawn (i.e. D&C) and accidentally dug out the roots of the grass, the grass would regrow after watering only in the areas where there were either some residual roots, or seeds. Imagining that the seeds are in a slightly deeper layer of soil (for the purpose of this analogy), if the gardener dug very deeply so that even the seeds were removed, no amount of watering would regrow the grass. This could happen in a patch of grass or the whole lawn. In this simple analogy the bald patches would be endometrial sclerosis (unstuck Asherman’s), but adhesions would result if two bald patches came into contact with eachother in the uterus.

More recently, the presence of endometrial stem cells at the myometrial junction was reported. These should be able to transform into endometrial stem cells with the right stimulation. The discovery of the existence of endometrial stem cells could explain why in some cases an apparently denuded endometrium (ie.no visible endometrium) will regenerate while in other cases it will not. Or why some women have recurring adhesions while others do not. This would explain why estrogen therapy after hysteroscopic adhesiolysis can in some cases stimulate the regerenation of endometrium while other cases of IUA are recurrent no matter the dose of estrogen therapy and the length of uterine barrier therapy. Endometrium is what keeps the myometrial layer of the uterus from adhering to opposing walls of the uterus. Once again, it is imposible to observe with the naked eye whether stem cells have been removed by curettage or not which would give rise to ‘paradoxical’ outcomes between patients with the ‘same’ severity of injury. In addition, differences in methods for dissecting adhesions can account for differing outcomes. Mechanical methods for adhesion dissection may also be preferable to methods which utilize thermal energy as the latter may damage adjacent tissue.

A modern perspective on an old problem

Authors need to re-evaluate the validity of assumptions, speculations and theories made in publications written when conditions and standards differed greatly to those of today, taking into consideration medical progress.   Although older papers are still important and interesting to read, they need to be interpreted carefully and in the context of limitations in medical technology and critical thinking, lower standards needed for proof and gaps in scientific understanding at the time they were written. Blind repetition of theories cited from papers that were published decades ago without any questioning is simply archaic, unrigorous and unscientific. If there is a case for a genetic or constitutional basis for AS, data from well designed studies would be more persuasive than citing theories which lack any experimental support of any kind. In what seems to be a recurring theme in AS, absence of evidence may not be evidence of absence, but by today’s standards in medicine only presence of evidence is evidence of presence.

A genetic predisposition: from speculation to opinion to 'fact' without any data (Part I)

The theory that Asherman’s syndrome has a ‘constitutional’ or ‘genetic’ basis has been making rounds for a while. It is time to critical appraise this idea with a view of our understanding of modern medicine.

From where did this theory originate and is there any evidence to support it? From my own thorough research of the literature on Asherman’s syndrome, having read most of the peer reviewed publications dating back to the early 60s, the first mention of the possibility of a hypothetical constitutional factor comes from a publication by Foix et al in 1966 (1). They write: (page 1028): "Besides the above-mentioned presidposing factors, there appears sometimes to be a constitutional element, for some of our patients treated for adhesions after each of several induced abortions, always developed new ones.” Thus they give no supporting references or evidence other than their own subjective observations.

Most reviews or studies mentioning this theory cite a review paper by Schenker and Margoliath in 1982 (2). In it they elaborate on the same ideas, citing a case series by Polishuk and Sadovsky in 1973 (3) as ‘support’. Schenker and Margoliath’s rationale was that:

a) some women develop a severe form of IUA after undergoing the ‘same’ traumatic procedures as others who do not acquire AS, and

b) some women respond more ‘favourably’ to treatment than others who suffer from recurrent adhesions.

They go further and conjecture that 28 women plucked from studies they compiled from the literature ‘may have possessed this predisposing factor, which might have been the reason for the development of IUA after normal delivery or following abortion without subsequent curettage, or even when lacking any attributable trauma.” This is a very bold, if not preposterous assertion to make about patients they have never examined or treated. Needless to say, diagnosis from a distance by third party observers is not a credible source of evidence.

The Polishuk and Sadovsky paper also fails to provide any proof. In fact, Polishuk and Sadovsky themselves never mentioned the idea of a genetic predisposition in their paper or set out to prove such a theory. Instead, they present a case series of 11 patients who have recurrent adhesions, one of three types of adhesions, they explain. Adhesions recurred in all cases after curettage for removal of adhesions or following abortion in a new pregnancy. They suggest that the patients in their study may have had extensive endometrial ‘repair’ i.e. fibrosis, where the endometrium is replaced by connective tissue, which they attempted to treat by removing it. Their understanding of cellular physiology, like their contemporaries, is incorrect but excusable given what was known at the the time it was written. They conclude that their treatment was not encouraging. It should not be surprising to doctors today that blind lysis using curettage is not a successful treatment for IUA or that the removal of fibrotic tissue does not result in endometrial regeneration. I will explain later...(Part II)

Since the speculation by Foix et al and later Schenker and Margoliath, numerous authors have subsequenty made it a habit to include this under etiology of AS, apparently without much thought. The theory also seems to have gained credibility with authors stating it as a fact rather than a hypothesis without any further ‘evidence’. The quality of referencing in many articles about Asherman’s syndrome is lacking. Some authors even cite other reviews which never made the speculation. Clearly, many authors simply copy references from other papers without ever reading the original article to confirm or verify what was actually written.

Back in 1948 Asherman himself seemed to have understood that the underlying cause of IUA are usually trauma from instrumentation (although severe infection, especially endometrial tuberculosis can also cause physical injury to the lining) when he named the condition ‘traumatic amenorrhea’ (4). Unfortunately, the medical community has since been trying to attribute other causes or factors necessary for its development (another example of this is ‘subclinical infection’) perhaps to redeem their dependence on blind curettage as a standard procedure, and also to compensate for their lack of understanding about cellular physiology and insight into the condition. The condition has also been renamed (or misnomered) ‘Asherman’s syndrome’ which distances it from an iatrogenic cause. The word ‘traumatic’ made some doctors feel uncomfortable (5):

(See Discussion Dr John Morton LA California): “The nomenclature also is objectionable. The “traumatic” part of the phrase indicates an iatrogenic lesion, which may not always be justified. (my edit: This is true, but many if not most cases are actually iatrogenic since surgery is involved).

(…)

Dr Jones (closing):It is true that the term “traumatic” is not wholly satisfactory, but it is the term most frequently used in current literature to describe the abnormality under discussion. H W Jones Jr has suggested that the term “postcurettage atresia of the endometrial cavity” is more descriptive, and this may avoid the iatrogenic connotation of the word “traumatic”.

(…)

Thus, there must be an inflammatory factor in the etiology of intrauterine adhesions (my edit: Trauma to the tissue causes inflammation-not to be confused with infection). Parenthetically this too underlines Dr Morton’s objection to the term ‘traumatic’.”

I won’t go into why the above reasoning is incorrect here, my point was to display the obvious discomfort doctors felt in acknowledging an iatrogenic etiology, which probably contributed to its eventual name change as well as the reason why the medical community is so willing to accommodate other unproven causes of Asherman’s syndrome. It’s as if the mentality with regards to Asherman’s syndrome is caught in a time warp where principles of modern medicine such as using modern techniques, well designed studies, objectivie interpretation of data and the requirement of evidence have been temporarily waived.

Although it is natural to consider the possibility that any condition may have a genetic basis, a current understanding of adhesions, the advent of hysteroscopy and techniques to view inside the uterus, a century of observations and plain common sense suggest that such an explanation is not only based on speculation and flawed thinking, and cannot obscure the lack of even the weakest level of research evidence (eg. a case study) exists to support it. Next time I will explain exactly why.

We know now that adhesions (whether intra unterine or intra abdominal) are not a pathological response: they are a normal physiological response to injury adjacent mucosa. Adhesions are only pathological in the sense that they can lead to pathologies such as infertility, bowel obstruction and pain, depending on their location. They are the end result of normal wound healing, of which inflammation (not to be confused with infection) is an inherent process. They occur very commonly in intraabdominal surgery because there is no regenerative layer unlike the uterus which is lined with a regenerative endometrium. Yet no intraabdominal surgeon has attempted to label the condition as ‘genetic’ or ‘constitutional. However, not surprisingly, the endometrium will not regenerate if it is entirely removed, which should not occur during curettage, but which may happen unintentionally due to the blind nature of the procedure. The situation in the uterus then becomes analogous to that in the peritoneum, and adhesion formation ensues.

Lastly, with regards to Polishuk and Sadovsky’s paper, if anything, these cases should highlight the dangers of blind curettage as a method of treating Asherman’s syndrome and miscarriage, the latter particularly in women who have had Asherman’s syndrome. It would appear that endometrial damage leading to AS predisposes to further adhesions probably by facilitating injury, even after previous treatment to restore an open cavity. This is consistent with the observation that even after corrective surgery, women who have a history of Asherman’s syndrome are at an increased risk of specific obstetric complications. It is therefore of no surprise that the common underlying characteristic of these complications is a defective utero-placental interface.

REFERENCES

1.  Foix A, Bruno RO, Davison T, Baltasar L. The pathology of postcurettage intrauterine adhesions. Am J Obst & Gynec.1966; 96(7):1027-33.
2. Schenker JG, Margoliath EJ. Intrauterine adhesions: an updated appraisal. 1982; 37(5):593-610.
3. Polishuk WZ, Sadovsky E. A syndrome of recurrent intrauterine adhesions. Am J Obstet Gynecol 1975 151-8.
4. Asherman J, Amenorrhoea traumatic (Atretica). J Obstet Gynecol 1948; Br Emp 55:23.
5. Jones W. Traumatic Intrauterine adhesion; a report of 8 cases with emphasis on therapy. Am J Obstet & Gynec 1964; 89(3):304-13.

Articles on Asherman's syndrome Diagnosis, Classification and Treatment

Further publications on Asherman's syndrome have been added to the site. These include those on the Diagnosis, Classification and Treatment of Asherman's syndrome. Please click here or on the relevant tab in the menu above to view these references.

Previously a page with references to studies on the Etiology, Incidence and Prevention of Asherman's syndrome was added. Click here or on the relevant tab in the menu above for more.

Further references to publications on Asherman's syndrome by topic will be added to the site in the near future.

Alternative perspectives?

Some months ago, a fellow Asherman’s syndrome (AS) sufferer who writes the blog Alternative Asherman’s had a missed miscarriage after AS and wrote of her experience (Three steps backwards) using misoprostol, linking it to the blog about my own experience using misoprostol. I feel it is necessary to clarify certain points in her experience as they may be inadvertantly misleading and appear to implicate misoprostol in what apparently ensued. She has also since updated her blog to clarify her interpretation of her experience.

Misoprostol is a non-invasive uterotonic drug that expels the uterine contents in a way that is analogous to a natural miscarriage. Scarring and subsequent adhesions are the result of physical injury (or severe infection) to the basal endometrium. In fact management of miscarriage with misoprostol has been shown to prevent adhesion formation compared to blind D&C (Tam WH, Lau WC, Cheung LP, Yuen PM, Chung TK. J Am Assoc Gynecol Laparosc.2002; 9 (2): 182–185.). Misoprostol can be used to expel the contents of the uterus for either pregnancy termination, after a missed or incomplete miscarriage has occured or for labour induction. It also dilates the cervix and is useful prior to hysteroscopic surgery. Unfortunately, misoprostol is often referred to as a 'pregnancy termination drug' despite its various uses.

With regards to misoprostol's efficacy it should be noted that she obtained Chinese herbs from her accupuncturist to help 'prepare her body for miscarriage'. (See her comment below). This is unnecessary. It is not advised to mix Chinese or any other alternative or over the counter drug/herb with the treatment prescribed by your qualified ObGyn. Any responsible qualified homeopath/alternative medicine practitioner (some are MDs) would not dispense drugs whose effects and interactions with drugs prescribed by another specialist is not known and has not been vigorously trialed. There is no regulation or standardization of alternative drugs (herbs, extracts, etc.) so their concentrations, compositions quality and therefore effects and interactions vary greatly. We don't know if using these herbs could have interfered with misoprostol's effect in some way (for example, reducing its efficacy by blocking the same receptors targeted by misoprostol).

She was told that she developed IUA after using misoprostol and prior to hysteroscopic surgery to remove retained products. Her hysteroscopic surgeon said that the RPOC from an incomplete evacuation led to fibrous scar tissue formation. While I have heard about this anecdotally, I have not seen any reports of women developing IUA from RPOC in the absence of severe infection. It is also difficult to reconcile the observation of dense scar tissue with products retained for just 5 weeks when scar tissue is not complete until about 8 weeks. Anecdotally, I personally had substantial retained products for 3 weeks after my second trimester miscarriage treated with misoprostol and did not develop IUA. RPOC and retained placenta can be managed conservatively (under medical supervision).

However, she does mention that she may have already had some recurrence of IUA before her pregnancy as her Obstetrician noticed what appeared to be synechiae on ultrasound. This appears to be an important clue.

She says that there were dense adhesions whereas she previously had had only mild adhesions at initial diagnosis.One possible way to explain the deterioration of her condition could lie in the initial treatment of her AS: she had a uterine cook balloon inserted following adhesiolysis. While I underwent the same procedure without any apparent complications like hundreds of others (a proportion of whom have gone on to have children), it is possible that if the stent was not removed properly, or if it somehow adhered to raw surfaces in the uterus, it could have caused damage on removal (the balloon is deflated and simply pulled out). This explanation would also be consistent with her ObGyn's observation of scar tissue during a prenatal scan. Note also that there is limited data from studies on the benefits of using the Foley catheter and IUDs after surgical lysis and no controlled or comparative trials on the Cook balloon. Some Asherman’s syndrome specialists even believe that stents can stunt endometrial regrowth.

A well researched and routinely used drug like misoprostol should not be treated with suspicion compared to many other medical and even pseudo medical treatments the same women undergo without questioning, from unproven and potentially harmful altnernative drugs to contraversial fertility therapies to treatments of Asherman’s syndrome on which there are comparatively less data and of a lower quality. This leads me to wonder whether it is the attitude of the treating doctor(s) which influences patients' perceptions of treatments. I agree that more doctors need to be trained in the use of misoprostol for miscarriage (and in particular among women with a history of AS) and that a followup hysteroscopy may be needed depending on clinical symptoms and gestational age at time of miscarriage to ensure there are no retained products of conception. Followup hysteroscopy may also be necessary in women with a history of AS if the miscarriage passed naturally as there is a possible tendency towards retained tissue from scarring. We already know that women with past AS are at an increased risk of abnormally invasive placentation such as placenta accreta. Retained tissue and placenta accreta may be different ends of a spectrum of abnormalities associated with placental invasion in a defective endometrium. Whether misoprostol is necessary to evacuate miscarriages that occur very early on in the pregnancy (prior to 7 weeks) is also questionable. These can be managed expectantly. It is especially risky to perform a blind D&C in women who already have suffered damage to their uterine lining. It is time for miscarriage management as a whole to be reviewed in light of advances in medical therapy and hysterosopic alternatives.