Asherman’s Syndrome (AS) is an acquired gynecological condition characterized by the formation of scar tissue, known as intrauterine adhesions or synechiae, within the uterine cavity and often the cervix. These adhesions cause the walls of the uterus to stick together, which can partially or completely obliterate the internal space. Because the uterus is the site of embryo implantation and growth, this scarring is a significant cause of secondary infertility and recurrent miscarriage. Conception is frequently difficult or impossible without specialized intervention to clear the scar tissue and restore the uterine environment.
Defining Asherman’s Syndrome and Its Impact on Fertility
The formation of intrauterine adhesions most commonly occurs following a procedure that involves instrumentation of the uterus, particularly a Dilation and Curettage (D&C) performed after a miscarriage, an abortion, or for retained placental tissue after delivery. Trauma to the basal layer of the endometrium triggers an inflammatory response that results in scar tissue formation. The risk of developing this condition increases with the number of D&C procedures a person undergoes, especially when performed on a recently pregnant uterus.
The scar tissue physically reduces the size and distensibility of the uterine cavity. This limited space and the poor blood supply within the scarred tissue prevent the healthy development of the endometrium, which is necessary for a fertilized egg to implant and thrive. In mild cases, the adhesions may be thin and filmy, but in severe cases, the entire front and back walls of the uterus can fuse together.
A common symptom of Asherman’s Syndrome is a change in the menstrual pattern, often presenting as hypomenorrhea (unusually light flow) or amenorrhea (complete absence of menstruation). These symptoms occur because the functional layer of the endometrium is too damaged to grow and shed normally, or because the adhesions block the cervix, preventing menstrual blood from exiting. The reduced quantity and quality of the uterine lining are the primary mechanisms by which AS causes infertility and pregnancy loss.
Treatment Options for Restoring Fertility
Restoring fertility requires a surgical procedure known as hysteroscopic lysis of adhesions, which is the standard of care. This minimally invasive surgery is performed using a hysteroscope, a thin telescope inserted through the vagina and cervix into the uterus. The hysteroscope allows the surgeon to visualize the adhesions directly on a monitor.
Under direct visualization, specialized micro-instruments, such as fine scissors or an electrosurgical device, are used to meticulously cut and separate the scar tissue bands. The goal is to restore the normal shape and volume of the uterine cavity while preserving as much of the remaining healthy endometrial tissue as possible. This procedure often takes place in multiple stages, particularly in cases of severe or dense scarring, to minimize the risk of uterine perforation.
Post-operative management is designed to prevent the recurrence of adhesions, which can happen rapidly as the uterus heals. A temporary barrier, such as a small balloon catheter or an intrauterine device (IUD), is often placed in the cavity for several days to keep the newly separated walls from touching and re-scarring. High-dose estrogen therapy is also prescribed for a period of weeks to stimulate the growth and regeneration of the remaining healthy endometrial lining.
Pregnancy Success and Potential Complications
Following successful hysteroscopic treatment, the chance of conception and carrying a pregnancy to term is highly variable and depends on the initial severity of the adhesions. Studies show overall pregnancy rates ranging from 40% to 50% after treatment, with live birth rates generally falling between 30% and 60%. Individuals with mild scarring and younger age tend to have the most favorable outcomes.
While the surgery can restore the uterine cavity’s shape, underlying damage to the endometrium often results in an increased risk of complications during pregnancy. The most concerning risks relate to placental attachment, collectively known as abnormally invasive placentation. This includes conditions like Placenta Accreta, where the placenta grows too deeply into the uterine wall, potentially leading to severe hemorrhage at delivery.
The risk of miscarriage and preterm birth also remains elevated following treatment for Asherman’s Syndrome. Miscarriage rates may be as high as 20% to 30%, attributed to the reduced quality of the uterine lining and compromised blood flow to the developing fetus. Due to the history of uterine trauma and potential placental complications, these pregnancies are managed as moderate to high-risk, requiring careful monitoring, often including specialized ultrasounds, throughout gestation.