Asherman's syndrome (AS) is an acquired uterine condition that occurs when scar tissue (
adhesion
Adhesion is the tendency of dissimilar particles or interface (matter), surfaces to cling to one another. (Cohesion (chemistry), Cohesion refers to the tendency of similar or identical particles and surfaces to cling to one another.)
The ...
s) forms inside the uterus and/or the cervix.
It is characterized by variable scarring inside the uterine cavity, where in many cases the front and back walls of the uterus stick to one another. AS can be the cause of menstrual disturbances, infertility, and placental abnormalities. Although the first case of intrauterine adhesion was published in 1894 by Heinrich Fritsch, it was only after 54 years that a full description of Asherman syndrome was carried out by
Joseph Asherman.
Several other terms have been used to describe the condition and related conditions including: uterine/cervical atresia, traumatic uterine atrophy, sclerotic endometrium, and endometrial sclerosis.
There is no one cause of AS. Risk factors can include
myomectomy,
cesarean section, infections, age, genital
tuberculosis
Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can al ...
, and
obesity
Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classifi ...
. Genetic predisposition to AS is being investigated. Some studies show that a severe pelvic infection, independent of surgery may cause AS. AS can develop even if the woman has not had any uterine surgeries, trauma, or pregnancies. While rare in North America and European countries, genital tuberculosis is a cause of Asherman's in other countries such as India.
History
The condition was first described in 1894 by
Heinrich Fritsch (Fritsch, 1894) and further characterized by the
Israeli gynecologist
Joseph Asherman (1889–1968) in 1948.
It is also known as Fritsch syndrome, or Fritsch-Asherman syndrome.
Signs and symptoms
It is often characterized by a decrease in flow and duration of bleeding (
absence of menstrual bleeding,
little menstrual bleeding, or
infrequent menstrual bleeding)
and
infertility
In biology, infertility is the inability of a male and female organism to Sexual reproduction, reproduce. It is usually not the natural state of a healthy organism that has reached sexual maturity, so children who have not undergone puberty, whi ...
.
Menstrual anomalies are often but not always correlated with severity: adhesions restricted to only the
cervix
The cervix (: cervices) or cervix uteri is a dynamic fibromuscular sexual organ of the female reproductive system that connects the vagina with the uterine cavity. The human female cervix has been documented anatomically since at least the time ...
or lower
uterus
The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...
may block
menstruation
Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and Mucous membrane, mucosal tissue from the endometrium, inner lining of the uterus through the vagina. The menstrual cycle is characterized ...
. Pain during
menstruation
Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and Mucous membrane, mucosal tissue from the endometrium, inner lining of the uterus through the vagina. The menstrual cycle is characterized ...
and
ovulation
Ovulation is an important part of the menstrual cycle in female vertebrates where the egg cells are released from the ovaries as part of the ovarian cycle. In female humans ovulation typically occurs near the midpoint in the menstrual cycle and ...
is sometimes experienced and can be attributed to blockages.
It has been reported that 88% of AS cases occur after a
D&C is performed on a recently
pregnant
Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins.
Conception (biology), Conception usually occurs ...
uterus
The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...
, following a missed or incomplete
miscarriage
Miscarriage, also known in medical terms as a spontaneous abortion, is an end to pregnancy resulting in the loss and expulsion of an embryo or fetus from the womb before it can fetal viability, survive independently. Miscarriage before 6 weeks ...
,
birth
Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...
, or during an elective termination (
abortion
Abortion is the early termination of a pregnancy by removal or expulsion of an embryo or fetus. Abortions that occur without intervention are known as miscarriages or "spontaneous abortions", and occur in roughly 30–40% of all pregnan ...
) to remove
retained products of conception.
Causes
The cavity of the
uterus
The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...
is lined by the
endometrium
The endometrium is the inner epithelium, epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer: the basal layer contains stem cells which regenerate the functional layer. The funct ...
. This lining is composed of two layers, the
functional layer (adjacent to the uterine cavity) which is shed during
menstruation
Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and Mucous membrane, mucosal tissue from the endometrium, inner lining of the uterus through the vagina. The menstrual cycle is characterized ...
and an
underlying basal layer (adjacent to the myometrium), which is necessary for regenerating the
functional layer. Trauma to the basal layer, typically after a
dilation and curettage (D&C) performed after a
miscarriage
Miscarriage, also known in medical terms as a spontaneous abortion, is an end to pregnancy resulting in the loss and expulsion of an embryo or fetus from the womb before it can fetal viability, survive independently. Miscarriage before 6 weeks ...
, or
delivery, or
abortion
Abortion is the early termination of a pregnancy by removal or expulsion of an embryo or fetus. Abortions that occur without intervention are known as miscarriages or "spontaneous abortions", and occur in roughly 30–40% of all pregnan ...
, can lead to the development of intrauterine scars resulting in
adhesions that can obliterate the cavity to varying degrees. In the extreme, the whole cavity can be scarred and occluded. Even with relatively few scars, the
endometrium
The endometrium is the inner epithelium, epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer: the basal layer contains stem cells which regenerate the functional layer. The funct ...
may fail to respond to
estrogen
Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...
.
Asherman's syndrome affects women of all races and ages equally, suggesting no underlying genetic predisposition for its development.
AS can result from other pelvic surgeries including
cesarean sections,
removal of fibroid tumours ( myomectomy) and from other causes such as IUDs, pelvic irradiation, schistosomiasis
Schistosomiasis, also known as snail fever, bilharzia, and Katayama fever is a neglected tropical helminthiasis, disease caused by parasitism, parasitic Schistosoma, flatworms called schistosomes. It affects both humans and animals. It affects ...
and genital tuberculosis. Chronic endometritis from genital tuberculosis is a significant cause of severe intrauterine adhesions (IUA) in the developing world, often resulting in total obliteration of the uterine cavity which is difficult to treat.
An artificial form of AS can be surgically induced by endometrial ablation in women with excessive uterine bleeding, in lieu of hysterectomy
Hysterectomy is the surgical removal of the uterus and cervix. Supracervical hysterectomy refers to removal of the uterus while the cervix is spared. These procedures may also involve removal of the ovaries (oophorectomy), fallopian tubes ( salpi ...
.
Diagnosis
The history of a pregnancy
Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins.
Conception (biology), Conception usually occurs ...
event followed by a D&C leading to secondary amenorrhea or hypomenorrhea is typical. Hysteroscopy is the gold standard for diagnosis.[ Imaging by sonohysterography or hysterosalpingography will reveal the extent of the scar formation. Ultrasound is not a reliable method of diagnosing Asherman's Syndrome. Hormone studies show normal levels consistent with reproductive function.
]
Classification
Various classification systems were developed to describe Asherman's syndrome (citations to be added), some taking into account the amount of functioning residual endometrium, menstrual pattern, obstetric history, and other factors which are thought to play a role in determining the prognosis. With the advent of techniques that allow visualization of the uterus, classification systems were developed to take into account the location and severity of adhesions inside the uterus. This is useful as mild cases with adhesions restricted to the cervix may present with amenorrhea and infertility, showing that symptoms alone do not necessarily reflect severity. Other patients may have no adhesions but amenorrhea and infertility due to a sclerotic atrophic endometrium. The latter form has the worst prognosis.
Prevention
A 2013 review
A review is an evaluation of a publication, product, service, or company or a critical take on current affairs in literature, politics or culture. In addition to a critical evaluation, the review's author may assign the work a content rating, ...
concluded that no studies were reporting on the link between intrauterine adhesions and long-term reproductive outcome after miscarriage, while similar pregnancy outcomes were reported after surgical management (e.g. D&C), medical management or conservative management (that is, watchful waiting
Watchful waiting (also watch and wait or WAW) is an approach to a medical problem in which time is allowed to pass before medical intervention or therapy is used. During this time, repeated testing may be performed.
Related terms include ''expe ...
).[ There is an association between surgical intervention in the uterus and the development of intrauterine adhesions, and between intrauterine adhesions and pregnancy outcomes, but there is still no clear evidence of any method of prevention of adverse pregnancy outcomes.][
In theory, the recently pregnant uterus is particularly soft under the influence of hormones and hence, easily injured. D&C (including dilation and curettage, dilation and evacuation/suction curettage, and manual vacuum aspiration) is a blind, invasive procedure, making it difficult to avoid endometrial trauma. Medical alternatives to D&C for evacuation of retained placenta/products of conception exist, including misoprostol and ]mifepristone
Mifepristone, and also known by its developmental code name RU-486, is a drug typically used in combination with misoprostol to bring about a medical abortion during pregnancy. This combination is 97% effective during the first 63 days (9 wee ...
. Studies show this less invasive and cheaper method to be an efficacious, safe and an acceptable alternative to surgical management for most women. It was suggested as early as 1993[ that the incidence of IUA might be lower following medical evacuation (e.g., Misoprostol) of the uterus, thus avoiding any intrauterine instrumentation. So far, one study supports this proposal, showing that women who were treated for missed miscarriage with misoprostol did not develop IUA, while 7.7% of those undergoing D&C did.] The advantage of misoprostol is that it can be used for evacuation not only following miscarriage, but also following birth for retained placenta or hemorrhaging.
Alternatively, D&C could be performed under ultrasound guidance rather than as a blind procedure. This would enable the surgeon to end scraping the lining when all retained tissue has been removed, avoiding injury.
Early monitoring during pregnancy to identify miscarriage can prevent the development of, or, as the case may be, the recurrence of AS, as the longer the period after fetal death following D&C, the more likely adhesions may be to occur.[ Therefore, immediate evacuation following fetal death may prevent IUA.The use of hysteroscopic surgery instead of D&C to remove retained products of conception or placenta is another alternative that could theoretically improve future pregnancy outcomes, although it could be less effective if tissue is abundant. Also, hysteroscopy is not a widely or routinely used technique and requires expertise.
There is no data to indicate that suction D&C is less likely than sharp curettage to result in Asherman's. A recent article describes three cases of women who developed intrauterine adhesions following manual vacuum aspiration.]
Intrauterine adhesions also form after hysteroscopic surgery such as myomectomy, polypectomy or septum removal. Mechanical barriers such as Womed Leaf or hyaluronic acid gels can be used to prevent formation of IUA after such adhesiogenic procedures or after D&C.
Treatment
Fertility may sometimes be restored by the removal of adhesions, depending on the severity of the initial trauma and other individual patient factors. Operative hysteroscopy is used for visual inspection of the uterine cavity during adhesion dissection (adhesiolysis). However, hysteroscopy is yet to become a routine gynaecological procedure and only 15% of US gynecologists perform office hysteroscopy. Adhesion dissection can be technically difficult and must be performed with care to not create new scars and further exacerbate the condition. In more severe cases, adjunctive measures such as laparoscopy are used in conjunction with hysteroscopy as a protective measure against uterine perforation. Microscissors are usually used to cut adhesions. Electrocauterization is not recommended.[
]
As IUA frequently reforms after surgery, techniques have been developed to prevent the recurrence of adhesions. Methods to prevent adhesion reformation include the use of mechanical barriers (Foley catheter, saline-filled balloon uterine stents, gel barriers (Seprafilm, Spraygel, autocrosslinked hyaluronic acid
Hyaluronic acid (; abbreviated HA; conjugate base hyaluronate), also called hyaluronan, is an anionic, nonsulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. It is unique among glycosaminog ...
gel Hyalobarrier) and mechanical barrier film (Womed Leaf) to maintain opposing walls apart during healing, thereby preventing the reformation of adhesions. A common pharmacological method for preventing reformation of adhesions is sequential hormonal therapy with estrogen
Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...
followed by a progestin to stimulate endometrial growth and prevent opposing walls from fusing.[ However, there have been no randomized controlled trials (RCTs) comparing post-surgical adhesion reformation with and without hormonal treatment, and the ideal dosing regimen or length of estrogen therapy is not known. A recent meta-analysis compared different post-surgical prevention barrier strategies and concluded that there was no single superior treatment. Furthermore, diagnostic severity and outcomes are assessed according to different criteria (e.g., menstrual pattern, adhesion reformation rate, conception rate, live birth rate). More comparable studies are needed in which reproductive outcomes can be analysed systematically. However, the latest randomized controlled trial, published in July 2024, demonstrated a clinically significant improvement in a group of patients with Asherman syndrome who received the Womed Leaf mechanical barrier film compared to a control group where no adhesion prevention tool was used.]
Follow-up tests (HSG, hysteroscopy or SHG) are necessary to ensure that adhesions have not reformed. Further surgery may be necessary to restore a normal uterine cavity. According to a recent study among 61 patients, the overall rate of adhesion recurrence was 27.9%. In moderate and severe cases, it is up to 76%.
Prognosis
The extent of adhesion formation is critical. Mild to moderate adhesions can usually be treated successfully. Extensive obliteration of the uterine cavity or fallopian tube openings ( ostia) and deep endometrial or myometrial trauma may require several surgical interventions and/or hormone therapy or even be uncorrectable. If the uterine cavity is adhesion-free but the ostia remain obliterated, IVF remains an option. If the uterus has been irreparably damaged, surrogacy
Surrogacy is an arrangement whereby a woman gets pregnant and gives birth on behalf of another person or couple who will become the child's legal parents after birth. People pursue surrogacy for a variety of reasons such as infertility, danger ...
or adoption
Adoption is a process whereby a person assumes the parenting of another, usually a child, from that person's biological or legal parent or parents. Legal adoptions permanently transfer all rights and responsibilities, along with filiation, fro ...
may be the only options.
Depending on the degree of severity, AS may result in infertility
In biology, infertility is the inability of a male and female organism to Sexual reproduction, reproduce. It is usually not the natural state of a healthy organism that has reached sexual maturity, so children who have not undergone puberty, whi ...
, repeated miscarriages, pain from trapped blood, and future obstetric complications If left untreated, the obstruction of menstrual flow resulting from adhesions can lead to endometriosis
Endometriosis is a disease in which Tissue (biology), tissue similar to the endometrium, the lining of the uterus, grows in other places in the body, outside the uterus. It occurs in women and a limited number of other female mammals. Endomet ...
in some cases.
Patients who carry a pregnancy
Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins.
Conception (biology), Conception usually occurs ...
even after treatment of IUA may have an increased risk of having abnormal placentation including placenta accreta where the placenta invades the uterus
The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...
more deeply, leading to complications in placental separation after delivery. Premature delivery, second-trimester pregnancy loss, and uterine rupture are other reported complications. They may also develop incompetent cervix where the cervix can no longer support the growing weight of the fetus, the pressure causes the placenta to rupture, and the mother goes into premature labour. Cerclage is a surgical stitch that helps support the cervix if needed.[
Pregnancy and live birth rates have been reported to be related to the initial severity of the adhesions, with 93, 78, and 57% pregnancies achieved after treatment of mild, moderate, and severe adhesions, respectively, and resulting in 81, 66, and 32% live birth rates, respectively.][ The overall pregnancy rate after adhesiolysis was 60%, and the live birth rate was 38.9% according to one study.][
]
Age is another factor contributing to fertility outcomes after treatment of AS. For women under 35 years of age treated for severe adhesions, pregnancy rates were 66.6% compared to 23.5% in women older than 35.[
]
Epidemiology
AS has a reported incidence of 25% of D&Cs performed 1–4 weeks post-partum, up to 30.9% of D&Cs performed for missed miscarriages and 6.4% of D&Cs performed for incomplete miscarriages. In another study, 40% of patients who underwent repeated D&C for retained products of conception after missed miscarriage or retained placenta developed AS.
In the case of missed miscarriages, the time period between fetal demise and curettage may increase the likelihood of adhesion formation due to fibroblastic activity of the remaining tissue.
The risk of AS also increases with the number of procedures: one study estimated the risk to be 16% after one D&C and 32% after three or more D&Cs. However, a single curettage often underlies the condition.
In an attempts to estimate the prevalence
In epidemiology, prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seatbelt use) at a specific time. It is derived by comparing the number o ...
of AS in the general population, it was found in 1.5% of women undergoing hysterosalpingography HSG, and between 5 and 39% of women with recurrent miscarriage.[
]
After miscarriage, a review
A review is an evaluation of a publication, product, service, or company or a critical take on current affairs in literature, politics or culture. In addition to a critical evaluation, the review's author may assign the work a content rating, ...
estimated the prevalence of AS to be approximately 20% (95% confidence interval: 13% to 28%).
References
External links
* Sophie Blake talks about being diagnosed with Asherman's syndrome.
*
*
* (awareness, education, prevention)
*
{{DEFAULTSORT:Asherman's Syndrome
Fertility
Noninflammatory disorders of female genital tract
Health issues in pregnancy
Gynaecologic disorders
Pregnancy with abortive outcome
Disorders related to length of gestation and fetal growth
Syndromes affecting female reproductive system
Diseases named after discoverers