ASHERMAN SYNDROME (UTERINE SYNECHIA)
Asherman syndrome (uterine synechia) is scarring or occlusion of the uterine cavity after curettage, especially when surgery is performed after septic abortion or in the immediate postpartum period. (Though the same changes occur following therapeutic endometrial ablation, the term is generally not applied in that setting.) This scarring generally results from endometrial damage involving the basal layers (normal curettage, excessive curettage, curettage when infection is present or in the immediate postpartum period—some intra-uterine adhesions form in 30% of patients treated by curettage for missed abortion), or endometrial infection (tuberculosis or schistosomiasis). More than 90% of the cases occur following pregnancy-related curettage. A severe pelvic infection unrelated to surgery, including endometrial tuberculosis infections, may also lead to Asherman syndrome. (Chronic endometritis from genital tuberculosis is a signiﬁcant cause of severe intra-uterine scarring in the developing world, often resulting in total obliteration of the uterine cavity.) A less common cause of IUA is severe endometritis or ﬁbrosis following a myomectomy, metroplasty, or cesarean delivery. In some cases, the whole cavity may be scarred and occluded, resulting in secondary amenorrhea. Even with relatively few scars, the endometrium may fail to respond to estrogens, which means that there is a poor correlation between symptoms and the severity of scarring found.
The true prevalence of Asherman syndrome is unclear because of a lack of awareness of the symptoms or diagnosis and the nonspeciﬁc nature of the symptoms. Intrauterine scarring is estimated to affect 1.5% of women undergoing hysterosalpingography, between 5% and 39% of women with recurrent miscarriage, and up to 40% of patients who have undergone curettage for retained products of conception (incomplete abortion).
Patients with uterine synechia generally present with amenorrhea, hypomenorrhea, recurrent early pregnancy loss, or infertility depending on the extent and intrauterine location of adhesions. Pain during menstruation and ovulation is also sometimes experienced, and can be attributed to sequestration and obstruction. Most often the patient will have a history of one or more risk factors such as curettage or infection, and the temporal relation between these events and the onset of symptoms should be suggestive of intrauterine scar- ring. Hysteroscopy, sonohysterography, or hysterosalpingography may all be used to conﬁrm the diagnosis. Ultrasonography, without the use of saline infusion, is not a reliable method of diagnosing intrauterine scarring. It has been suggested that sequential administration of estrogen followed by progestogen can be used as the initial diagnostic procedure when intra-uterine scarring is suspected. Unfortunately, withdrawal bleeding occurs following administration of the steroids in most women with intrauterine adhesions, resulting in a lack of speciﬁcity of this approach. If left untreated, retrograde menstruation (if present) caused by outﬂow obstruction may result in the development of endometriosis.
When uterine synechiae are diagnosed, resection of intrauterine scars under hysteroscopic control (sometimes with laparoscopy used as a protective measure against uterine perforation), followed by intrauterine contraceptive device (IUCD) insertion and estrogen therapy may be curative, providing a return of normal menstrual function and fertility. Repeated scarring may occur in up to 50% of cases, necessitating postoperative follow-up or repeated treatment. For this reason, follow-up tests, including a hysterosalpingogram, hysteroscopy, or sonohysterography, are necessary to ensure that scars have not reformed. Patients who have undergone resection of intrauterine adhesions who subsequently become pregnant are at greater risk for having abnormal placentation, including placenta accreta.
The prognosis for these patients is a function of the initial severity: Small scars can usually be treated with success; extensive obliteration of the uterine cavity or fallopian tube ostia may require several surgical inter-ventions or even be uncorrectable. In these cases, surrogacy, in vitro fertili ation (IVF), or adoption may be the only alternatives.