Tuesday, February 22, 2011

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.


  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.