Asherman's syndrome is ‘uncommon’. How many times have I come across that sentence or a variation of it (Asherman’s syndrome is ‘rare’ or even ‘extremely rare’ etc.). They were my ObGyn’s famous last words too. Oh, how I wish they were true. A simple google search of Asherman’s syndrome will show that many links contain this inaccuracy. Even the reputable ncbi/nih writes:
"Asherman syndrome is a rare condition. In most cases, it occurs in women who have had several dilatation and curettage (D&C) procedures."
No true!!! It often happens after a single D&C procedure. How often? Well, according to various studies published in peer-reviewed medical journals, the actual incidence of intrauterine adhesions (IUA) after D&C for miscarriage ranges between 7.7% and 30%, and after a repeat procecure, up to 40%. To be clear, some of these studies are not new. However, there is no reason to suspect that incidence rates would change as the techniques used are for the most part the same. The main cause of IUA is blind instrumentation in a uterus softened by the presence of hormones (as in pregnancy). Even the more recent manual vacuum aspiration has been associated with IUA (Dalton et al, 2006). Furthermore, sharp/blunt/suction D&C are often all used in the same procedure. Anyone who is familiar with the literature on Asherman’s syndrome will know that the references below are cited as references in recent review papers (see Yu et al,2008; Kodaman and Arici, 2007). [Obviously an institutional (or personal) subscription is needed to view the entire article]. Another potential criticism about these studies is that they are not RCTs. (One is an RCT but it does not meet the criteria for inclusion in the Cochrane Collaboration 's library (click here for more details). For non-scientists/doctors, I will describe what RCTs and the Cochrane library are in further detail in a later blog. For now, suffice to say that RCTs meet the most rigorous standards of scientific methodology.) Unfortunately, to date there are NO RCTs on Asherman’s syndrome (including etiology and treatment) in the Cochrane database.
Nevertheless, according to the available studies on the topic, the following incidence rates have been reported:
1. Adoni et al (1982) found the incidence of IUA to be 30.9% after D&C for a ‘late’ miscarriage. This is taken to mean a missed miscarriage where the products of conception have not been expelled despite the pregnancy’s failure. IUA were detected via hysterography.
2. Golan et al.(1992) did a prospective analysis of 60 women and found that 16.7% of women undergoing D&C for missed miscarriage had IUA detected by hysteroscopy (gold standard method of diagnosis).
3. Friedler et al (1993) also did a prospective study on women with missed miscarriages who underwent D&C and found that 16 of the 98 patients, or 16.3%, had IUA detected by hysteroscopy.
4. Romer et al’s (1994) prospective study diagnosed IUA in 30.2% of women who had D&C for either missed or incomplete miscarriage. This was diagnosed hysteroscopically.
5. Westendorp et al (1998) prospectively examined wome who had repeat D&C for incomplete miscarriage or retained POC (after either miscarriage or delivery) and found that on hysteroscopy, a whopping 40% of them had IUA. 30% were severe.
6. Tam et al (2002) performed a prospective study on IUA incidence after D&C for missed or incomplete miscarriage and compared it to women treated expectantly or using misoprostol. They found that 7.7% of women in the D&C group developed IUA while none developed it in the misoprostol group or expectant group. Again, hysteroscopy, was used for detection.
7. Eriksen and Kaestel (1960) reported in their retrospective analysis that approximately 25% of women undergoing post partum curettage developed IUA.
I don’t know about you, but I find all this unsettling. Why didn’t anyone tell me this before I had a D&C?!
Asherman’s syndrome is thought to affect 5% of the population. I don’t recall if there is a particular reference for this, but I know I’ve heard a few Asherman’s syndrome specialists say it. Of course it is difficult to know the exact prevalence as many cases are not diagnosed. Also, some women may have it but not desire a further pregnancy so they never find out if they are infertile or have pregnancy complications associated with Asherman’s syndrome.
What is striking is that this incidence (5%), is not very different from the rate of conditions such as PCOS, another cause of infertility (which, by the way, is not iatrogenic...) Yet, when do you ever hear people say: PCOS is a rare condition?! You will read everywhere that PCOS is ‘common’ or ‘exceedingly common’. There are entire sections of gynecology journals devoted to this condition and hundreds of studies. Asherman’s syndrome, in contrast, is largely ignored by the medical community. Are doctors repeating the supposed ‘rarity’ of Asherman’ syndrome to make women feel that D&Cs are safer than they really are?
Perhaps this misconception once served a purpose- to prevent doctors from hesitating to perform D&Cs in situations where uterine evacuation was necessary and in a time when there was no other option, and to prevent patients from fearing a necessary treatment. Today this myth no longer serves a purpose. D&C is no longer a ‘necessary evil’ as there are other methods such as hysteroscopic guidance or uterus-evacuating drugs to obtain the same result- minus the serious complications.
The first step towards change would be to accept that Asherman’s syndrome is NOT rare.
References (in order of appearance in text)
Dalton VK, Saunders NA,Harris LH, Williams JA, Lebovic DI. Intrauterine adhesions after manual vacuum aspiration for early pregnancy failure. Fertil Steril 2006;85(6):1823 e1-3.
Kodaman, PH and Arici, A. Intra-uterine adhesions and fertility outcome: how to optimize success? Curr Opin Obstet Gynecol 2007;19(3):207-14.
Yu, D, Wong, YM, Cheong, Y, Xia, E, and Li, TC. Asherman syndrome--one century later. Fertil Steril 2008;89(4):759-79.
Adoni, A, Palti, Z, Milwidsky, A, and Dolberg, M. The incidence of intrauterine adhesions following spontaneous abortion. Int J Fertil 1982;27(2):117-8.
Golan, A, Schneider, D, Avrech, O, Raziel, A, Bukovsky, I, and Caspi, E. Hysteroscopic findings after missed abortion. Fertil Steril 1992;58(3):508-10.
Friedler, S, Margalioth, EJ, Kafka, I, and Yaffe, H. Incidence of post-abortion intra-uterine adhesions evaluated by hysteroscopy--a prospective study. Hum Reprod 1993;8(3):442-4.
Romer, T. Post-abortion-hysteroscopy--a method for early diagnosis of congenital and acquired intrauterine causes of abortions. Eur J Obstet Gynecol Reprod Biol 1994;57(3):171-3.
Tam, WH, Lau, WC, Cheung, LP, Yuen, PM, and Chung, TK. Intrauterine adhesions after conservative and surgical management of spontaneous abortion. J Am Assoc Gynecol Laparosc 2002;9(2):182-5.
Westendorp, IC, Ankum, WM, Mol, BW, and Vonk, J. Prevalence of Asherman's syndrome after secondary removal of placental remnants or a repeat curettage for incomplete abortion. Hum Reprod 1998;13(12):3347-50.
Eriksen J, Kaestel C. The incidence of uterine atresia after post-partum curettage. A follow-up examination of 141 patients. Dan Med Bull 1960; 7:50-1.
- FAQs on Asherman’s syndrome
- How Asherman's syndrome causes infertility or misc...
- Frequency of intrauterine adhesions after D+C
- Management of Intrauterine Adhesions.
- Publications: Etiology, Incidence, Prevention
- Publications: Diagnosis, Classification and Treatm...
- Publications: Reproductive Outcomes, Obstetric Com...
- Introduction: why blog about Ashermans syndrome?
- About me