Endometriosis & Uterine Scarring: How They Affect Fertility Together

There is a particular kind of exhaustion that comes from having two conditions — both serious, both affecting your fertility, both chronically underdiagnosed — and being told by doctor after doctor that one of them doesn't exist, or that they have nothing to do with each other.

If you have endometriosis and you are also struggling with very light periods, implantation failure, or unexplained infertility, I want you to hear this clearly: it is entirely possible to have both endometriosis and intrauterine scarring at the same time. Not only is it possible — it is more common than most gynaecologists acknowledge. And the two conditions interact in ways that can make fertility significantly harder to achieve.

This article is for the women sitting in the overlap. The ones whose endo diagnosis felt like an answer, until it didn't explain everything. The ones who have done three IVF cycles with good embryos and still no baby. The ones whose periods have almost vanished since their laparoscopy. I see you. Let's talk through what might actually be going on.

Endometriosis vs Intrauterine Adhesions — What Is the Difference?

Endometriosis is a condition in which tissue similar to the uterine lining (endometrium) grows outside the uterus — on the ovaries, fallopian tubes, bladder, bowel, or elsewhere in the pelvis. This tissue responds to hormonal cycles the same way the lining inside the uterus does: it thickens, bleeds, and inflames. But because it has nowhere to go, it causes pain, inflammation, and — over time — scarring in the pelvic cavity.

Intrauterine adhesions (Asherman's syndrome) are a different thing entirely. These are bands of scar tissue that form inside the uterine cavity itself, causing the walls of the uterus to stick together, reducing functional space, and damaging the endometrial lining that an embryo needs in order to implant.

The distinction matters enormously, because the treatments are different, the diagnostic tools are different, and the fertility implications are different. Endometriosis is managed with hormonal therapy and surgery to remove lesions. Intrauterine adhesions are diagnosed with hysteroscopy and treated by surgically removing the scar tissue from inside the uterine cavity.

Many women — and many doctors — use the words "adhesions" interchangeably to describe both. This is a source of enormous confusion and diagnostic error.

How Endometriosis Surgery Can Cause Intrauterine Adhesions

Here is the connection that almost nobody talks about: the surgery used to treat endometriosis can itself cause Asherman's syndrome.

During a laparoscopy for endometriosis, surgeons may need to remove adhesions from the outside of the uterus, from the fallopian tubes, or occasionally from endometriomas (chocolate cysts) that have involved the ovaries. In cases where endometrial lesions are found inside the uterine cavity — a condition called adenomyosis or endometrial involvement — the uterine wall itself may be operated on.

Any procedure that involves the inside of the uterus, including hysteroscopy to remove endometrial polyps or lesions, carries a risk of intrauterine scarring as a direct result of the healing process. This risk increases with the complexity of the surgery, the presence of infection, and the number of repeat procedures.

According to Medical News Today, endometriosis surgery is itself a recognised cause of adhesion formation — not just a treatment for it. A woman can go into a laparoscopy to treat her endo and come out with new scarring, either pelvic adhesions from external surgery, or intrauterine adhesions if the cavity was entered.

This is not a failure of surgery. It is an acknowledged risk of healing. But it is one that far too few surgeons discuss with their patients beforehand — and one that far too few gynaecologists consider when a patient returns reporting changed periods or infertility after their procedure.

Pelvic Adhesions vs Intrauterine Adhesions — Why the Distinction Matters

Endometriosis commonly causes pelvic adhesions — bands of scar tissue that form outside the uterus, binding organs like the bowel, ovaries, and uterus to each other or to the pelvic wall. According to WebMD, these adhesions can cause pelvic pain, painful intercourse, bowel symptoms, and impaired egg transport — because when scar tissue forms in or around the fallopian tubes, it makes it harder for sperm to reach the egg and for the fertilised egg to travel to the uterus.

But pelvic adhesions do not directly damage the uterine lining. They are an external problem. Intrauterine adhesions are an internal problem. And when women with endometriosis also develop intrauterine adhesions — whether from the disease itself or from surgery to treat it — they have both external and internal barriers to pregnancy.

Pelvic adhesions may show up on imaging. Intrauterine adhesions frequently do not. A normal ultrasound or even a normal laparoscopy finding does not rule out Asherman's syndrome. Only a hysteroscopy — a camera inside the uterine cavity — can do that.

Shared Symptoms: Where Endo and Asherman's Overlap

One of the reasons the co-occurrence of these conditions goes unrecognised for so long is that their symptoms can look almost identical on the surface.

Both endometriosis and intrauterine adhesions can cause:

• Pelvic pain — though the character differs. Endo pain is often inflammatory and cyclical. Asherman's pain can feel like cramping without flow, as though the period is "stuck."
• Light or absent periods (hypomenorrhoea or amenorrhoea) — a hallmark of moderate to severe intrauterine adhesions, but also seen in endo when inflammation disrupts hormonal signalling.
• Difficulty conceiving — endo reduces fertility through pelvic adhesions, tubal damage, and inflammatory effects on egg quality. Asherman's reduces fertility by impairing implantation.
• Implantation failure in IVF — a woman may have good embryos, good hormone levels, and still not achieve pregnancy, because the lining is either too thin, or structurally compromised by intrauterine adhesions.
• Recurrent miscarriage — both conditions are associated with early pregnancy loss, for different but overlapping reasons.
• Painful intercourse — often attributed solely to endo, but can also be a symptom of intrauterine scarring that distorts pelvic anatomy.

When a woman with endometriosis notices her periods have changed — particularly after a procedure — the change is often attributed to hormonal fluctuation, to the endo itself, or to post-surgical effects that are expected to resolve. The possibility that intrauterine scarring has developed is rarely considered without specific prompting.

The Inflammatory Environment Endometriosis Creates

Beyond the direct surgical risk, endometriosis may create conditions inside the uterus that make intrauterine adhesion formation more likely in the first place.

Endometriosis is a chronic inflammatory disease. The pelvis of a woman with advanced endometriosis contains elevated levels of inflammatory cytokines, prostaglandins, and immune cells. Research has shown that this chronic inflammatory state can impair endometrial receptivity — the lining's ability to respond to oestrogen and prepare for implantation — even when the lining is physically intact.

When this inflammatory environment is combined with any uterine procedure, the healing response may be exaggerated. Scar tissue formation is part of normal wound healing, but in a chronically inflamed uterine environment, the balance between healing and fibrosis can tip toward excessive scarring. This is one proposed mechanism for why some women develop intrauterine adhesions after relatively minor procedures that would not cause scarring in women without underlying inflammatory disease.

This also explains why some women with endo develop a thin, poorly responsive lining even without obvious intrauterine scarring — the inflammatory milieu may be directly impairing endometrial function at a cellular level.

IVF Outcomes in Women with Endo and a Thin or Compromised Lining

For women undergoing IVF, lining quality is one of the most important factors in implantation success. A minimum endometrial thickness of 7–8mm is typically required, with most clinicians preferring 8–10mm for a frozen embryo transfer. A trilaminar (three-layer) pattern is also associated with better outcomes.

Women with endometriosis are disproportionately represented among those who struggle with thin lining during IVF cycles. The reasons are multiple and overlapping: the inflammatory effects of endo on endometrial receptivity, possible underlying intrauterine adhesions that have not been diagnosed, reduced blood flow to the uterus, and in some cases the side effects of long-term GnRH agonist suppression used to manage endo before an IVF cycle.

If you have endometriosis and your IVF cycles have been cancelled or failed due to inadequate lining thickness, or if implantation has repeatedly not occurred despite high-quality embryos, it is worth asking your reproductive endocrinologist specifically about the possibility of co-existing intrauterine pathology. The question to ask is: "Has the inside of my uterine cavity been visualised directly with hysteroscopy?"

If the answer is no — or if the last hysteroscopy was performed before your most recent uterine procedure — the answer may be incomplete.

Why Women with Endo Should Also Be Screened for Asherman's

There is currently no standard protocol that mandates hysteroscopy screening for women with endometriosis. But there are compelling reasons why it should be discussed, particularly in the following situations:

• Your periods have changed since a uterine procedure (lighter, shorter, or absent)
• You are experiencing cyclical pain with little or no flow
• You have undergone laparoscopy, D&C, hysteroscopy, or caesarean section in addition to your endo diagnosis
• You have had one or more failed IVF cycles with good embryo quality
• Your lining consistently fails to reach the target thickness in a medicated FET cycle
• You have experienced recurrent miscarriage
• You have a history of uterine infection or post-operative fever following an endo procedure

If any of these apply, raising the question of a diagnostic hysteroscopy is entirely reasonable. It is not alarmist. It is thorough.

What to Tell Your Doctor If You Suspect Both

Advocating for yourself in this space requires being specific. Here is language that tends to be taken seriously:

"I have a diagnosis of endometriosis and I've also had [procedure]. Since then my periods have changed significantly — they are much lighter and I am experiencing cramping with almost no flow. I am concerned this may represent intrauterine adhesions. I would like to discuss whether a diagnostic hysteroscopy is appropriate."

If your doctor dismisses the concern or attributes the change in periods solely to your endo, you are entitled to ask: "How would you distinguish between endometriosis effects on my cycle and intrauterine adhesions without direct visualisation of my uterine cavity?" There is no good answer to that question other than hysteroscopy.

Keep a record of when your periods changed, what they were like before versus after, and any associated symptoms. Specific, timestamped information is far more compelling than a general description of lighter periods.

Symptom Overlap Checklist

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Medical Disclaimer: This article is written for general informational purposes only. It does not constitute medical advice, diagnosis, or treatment. Daniella is not a medical professional. The information presented here is based on publicly available research and personal experience and should not replace consultation with a qualified gynaecologist, reproductive specialist, or other medical professional. Always seek the advice of your doctor regarding your specific symptoms, circumstances, and treatment options. Full disclaimer