Scar tissue, medically known as adhesions or fibrosis, can prevent pregnancy by physically obstructing reproductive pathways or creating an environment hostile to embryo implantation. This tissue develops as part of the body’s healing process following injury or severe inflammation within the pelvis. When fibrous tissue forms on or inside reproductive organs, it interferes with the delicate functions necessary for conception. Adhesions can block the transport of sperm or an egg, or compromise the uterine lining where a fertilized embryo needs to attach.
How Scar Tissue Develops in the Reproductive Tract
Scar tissue formation is typically a response to significant inflammatory events or surgical trauma. A frequent cause is Pelvic Inflammatory Disease (PID), an infection often resulting from untreated sexually transmitted infections. PID triggers a widespread inflammatory response, and as the body repairs the damage, it lays down bands of fibrous tissue called adhesions.
Prior surgical procedures involving pelvic organs also trigger scarring. Operations such as a Cesarean section, removal of uterine fibroids (myomectomy), or dilation and curettage (D&C) can injure tissue and initiate the scarring cascade. Damage to the basal layer of the endometrium, the lining of the uterus, can lead to internal scar tissue, especially after procedures following a miscarriage or delivery.
Endometriosis is another condition that drives adhesion formation in the pelvis. When endometrial-like tissue grows outside the uterus, it causes chronic inflammation and internal bleeding. This constant cycle of irritation and repair results in dense scar tissue that can bind organs together, such as the ovaries and fallopian tubes, limiting their mobility and function.
Location-Specific Ways Scar Tissue Prevents Pregnancy
The mechanism by which scar tissue prevents pregnancy depends on its location within the reproductive anatomy.
Fallopian Tubes
Scarring within the fallopian tubes is a common cause of infertility. The tubes can become fully or partially blocked (tubal occlusion), physically stopping the sperm and egg from meeting for fertilization. Scar tissue can also destroy the microscopic cilia responsible for sweeping the egg toward the uterus. This damage can trap a fertilized egg, significantly increasing the risk of an ectopic pregnancy.
Uterus
Scar tissue inside the uterine cavity is known as Asherman’s Syndrome or intrauterine adhesions. These fibrous bands decrease the functional surface area of the endometrium, the tissue layer necessary for successful embryo implantation. Scarring can range from thin strands to thick sheets that obliterate the uterine space. Even partial scarring can compromise the blood supply, making the environment hostile to implantation or leading to recurrent pregnancy loss.
Cervix
Scarring can also impact the cervix, the narrow opening between the vagina and the uterus. Procedures used to treat abnormal Pap smears can lead to scar tissue that narrows the cervical canal, a condition called cervical stenosis. This physical narrowing blocks or significantly impedes the passage of sperm into the uterus. Severe cervical scarring may also alter the quality of cervical mucus, contributing to infertility.
Identifying Scar Tissue as a Cause of Infertility
Diagnosing scar tissue requires specialized medical imaging and often, direct visualization procedures. The initial screening tool is Hysterosalpingography (HSG), an X-ray procedure where a contrast dye is injected through the cervix into the uterus. As the dye flows through the uterine cavity and fallopian tubes, the doctor can detect blockages or irregularities caused by adhesions.
When intrauterine adhesions (Asherman’s Syndrome) are suspected, Hysteroscopy is the definitive diagnostic method. During this procedure, a thin camera is inserted through the cervix for direct visualization of the uterine cavity. This view enables precise assessment of the extent, density, and location of the scar tissue.
For scar tissue located outside the uterus, such as adhesions on the fallopian tubes or ovaries, Laparoscopy is often necessary. This minimally invasive surgical procedure involves inserting a camera and instruments through small abdominal incisions. Laparoscopy provides a comprehensive view of the pelvic anatomy, identifying external adhesions that may be distorting organs or preventing the fimbriae from capturing the egg.
Treatment and Assisted Reproduction Options
Management involves either surgical attempts to restore normal anatomy or using technology to bypass the obstruction. Surgical intervention, known as adhesiolysis, aims to remove or break up fibrous bands to restore organ function. For intrauterine adhesions, this is typically performed hysteroscopically by carefully cutting the scar tissue to open the uterine cavity.
Laparoscopic surgery removes external pelvic adhesions that may be twisting the fallopian tubes or encasing the ovaries. A challenge with surgery is the potential for scar tissue to reform as the body heals, sometimes requiring additional procedures. Physicians minimize recurrence risk by placing barriers or using specific medications during and after surgery.
When scar tissue has caused irreparable damage, Assisted Reproductive Technology (ART) offers an alternative. In Vitro Fertilization (IVF) is the most common solution, as it completely bypasses the need for functional fallopian tubes. IVF involves retrieving eggs, fertilizing them in a laboratory, and transferring the resulting embryo directly into the uterus. If scarring is limited to the cervix, Intrauterine Insemination (IUI) may be effective by placing washed sperm directly into the uterus, overcoming the physical barrier.