Several gynecological conditions can cause both pelvic pain and infertility, but the most common culprits are endometriosis, pelvic inflammatory disease from untreated infections, uterine fibroids, and adenomyosis. These conditions share a pattern: they create inflammation, scarring, or structural changes in the reproductive organs that interfere with conception while also triggering persistent pain. Understanding which condition is behind your symptoms matters because treatment differs significantly for each one.
Endometriosis
Endometriosis is the single most recognized cause of both chronic pelvic pain and infertility. It occurs when tissue similar to the uterine lining grows outside the uterus, attaching to the ovaries, fallopian tubes, and pelvic surfaces. These growths respond to hormonal cycles just like normal uterine tissue, creating inflammation and eventually scar tissue called adhesions.
The fertility impact is driven by a complex chain of problems. Adhesions and anatomical distortion can physically block egg release from the ovary, prevent the fallopian tube from picking up the egg, or obstruct sperm from reaching the tube at all. Beyond the mechanical barriers, endometriosis disrupts how receptive the uterine lining is to a fertilized embryo and can reduce ovarian reserve over time. It’s not just one broken link but several at once.
Pain plays its own role in the infertility picture. Endometriosis carries a ninefold increased risk of deep pain during intercourse, particularly when lesions infiltrate the tissue behind the uterus and around the rectum. Chronic pelvic pain that persists outside of periods can also reduce desire, arousal, and frequency of intercourse, all of which lower the chances of conception on a purely practical level.
Surgical removal of endometriosis lesions roughly doubles the pregnancy rate in women with mild disease. For moderate to severe cases, excision surgery also improves spontaneous conception, with estimates of a 10 to 25 percent increase in the likelihood of pregnancy over what would happen without intervention.
Pelvic Inflammatory Disease From Untreated STIs
Chlamydia and gonorrhea are the two sexually transmitted infections most likely to quietly cause lasting reproductive damage. The CDC notes that many people with these infections have no symptoms at all, which is precisely what makes them dangerous. Left untreated, either infection can ascend from the cervix into the uterus and fallopian tubes, triggering pelvic inflammatory disease (PID).
PID causes pelvic pain that can range from a dull, persistent ache to sharp pain with fever. The real long-term threat is scarring inside the fallopian tubes. Even a single episode of PID can leave enough scar tissue to partially or fully block the tubes, preventing sperm and egg from meeting. Repeated infections compound the risk dramatically. Tubal scarring from PID is one of the most preventable causes of infertility, since early antibiotic treatment for chlamydia or gonorrhea stops the progression before permanent damage occurs.
PID can also increase the risk of ectopic pregnancy, where a fertilized egg implants inside a damaged fallopian tube instead of the uterus. This is a medical emergency and a direct consequence of the internal scarring these infections leave behind.
Uterine Fibroids
Fibroids are noncancerous growths in or on the uterus, and whether they cause pain or infertility depends almost entirely on where they’re located. There are three main types based on position, and each behaves differently.
- Submucosal fibroids grow into the uterine cavity. These have the clearest link to infertility because they distort the space where an embryo needs to implant. Pregnancy and live birth rates are lower in women with submucosal fibroids, and surgical removal has been shown to improve pregnancy rates.
- Intramural fibroids grow within the muscular wall of the uterus. They appear to reduce fertility, particularly when they’re large enough to push into and distort the uterine cavity. Treatment recommendations for these remain less clear-cut.
- Subserosal fibroids grow on the outer surface of the uterus. These do not affect fertility outcomes, and removing them provides no benefit for conception.
Fibroids of any type can cause pelvic pressure or pain, lower back pain, and discomfort during intercourse. Heavy or prolonged periods are also common. The combination of pelvic pain and difficulty conceiving in someone with fibroids typically points to submucosal or large intramural growths as the source of both problems.
Adenomyosis
Adenomyosis is sometimes called endometriosis’s “cousin.” Instead of tissue growing outside the uterus, it grows into the muscular wall of the uterus itself, causing the uterus to enlarge and become tender. The most common symptoms are heavy menstrual bleeding (affecting about 50 percent of symptomatic cases), painful periods (30 percent), and irregular bleeding (20 percent). Pain during intercourse is also reported.
The fertility impact of adenomyosis works differently from endometriosis. The tissue invasion disrupts the inner layer of the uterine wall, altering the chemical signals that make the lining receptive to an embryo. Key molecules needed for implantation are underproduced or dysregulated in adenomyotic tissue, which helps explain why women with this condition experience higher rates of implantation failure and first-trimester miscarriage during IVF. Two prospective studies found that adenomyosis reduces implantation rates, clinical pregnancy rates, and ongoing pregnancy rates compared to women without the condition.
Adenomyosis has traditionally been considered a condition of women in their 40s and 50s, with about 80 percent of cases diagnosed in that age group. But roughly 20 percent of cases involve women under 40, and improved imaging with ultrasound and MRI is catching it earlier and more often in women still trying to conceive.
PCOS and Pelvic Pain
Polycystic ovary syndrome is one of the most common causes of infertility due to irregular or absent ovulation, but its relationship to pelvic pain is more nuanced than the other conditions on this list. Pelvic pain, bloating, abdominal cramping, and painful periods are all reported by women with PCOS, driven in part by hormonal imbalances and chronic low-grade inflammation.
However, when a woman with PCOS reports significant pelvic pain, it’s worth investigating whether endometriosis is also present. While true overlap of both conditions is uncommon in the general population (around 0.02 percent), the co-occurrence rate climbs sharply in women who seek care for pain or infertility. In women hospitalized for PCOS or those reporting both infertility and pelvic pain, rates of coexisting endometriosis have been observed as high as 70 percent. Both conditions share features like chronic inflammation and altered hormone signaling that can amplify pain even without visible endometriosis lesions.
The practical takeaway: PCOS alone typically causes infertility through ovulation problems rather than structural damage. If you have PCOS and also experience notable pelvic pain, the pain may point to a second condition that deserves its own evaluation.
How These Conditions Overlap
One of the challenges with pelvic pain and infertility is that these conditions don’t always appear in isolation. A woman with endometriosis may also have adenomyosis. Fibroids can coexist with either. A past episode of PID can leave tubal damage that complicates an already difficult picture from endometriosis-related adhesions. This layering effect means that identifying and addressing just one cause may not fully resolve either the pain or the fertility challenges.
Diagnosis typically involves a combination of pelvic exam, ultrasound, and sometimes MRI. Laparoscopy, a minimally invasive surgery, remains the definitive way to confirm endometriosis and can double as treatment when lesions are removed during the procedure. STI screening with simple swab or urine tests can rule out or identify infections before they progress. For fibroids and adenomyosis, imaging usually provides enough information to guide next steps.
The connection between pelvic pain and infertility is not coincidental. Both symptoms often trace back to the same underlying process: inflammation, tissue damage, or structural distortion in the reproductive organs. Treating one frequently improves the other, which is why getting a specific diagnosis rather than managing symptoms in isolation tends to lead to better outcomes on both fronts.