Unexplained Infertility:
Could Uterine Scarring Be the Answer?

If you've been through a standard fertility workup and come out the other side with an "unexplained infertility" label, I want you to know something: that label is not the end of the story. For many women — especially those who've had a D&C, a miscarriage, or a uterine procedure — it's the beginning of one that hasn't been properly told yet.

One of the most frequently missed chapters in that story is uterine scarring. Specifically, a condition called Asherman's syndrome — intrauterine adhesions that form inside the uterine cavity and can silently disrupt implantation, cause miscarriage, and make it feel like your body has simply stopped cooperating.

What "Unexplained Infertility" Actually Means

"Unexplained infertility" sounds precise, but it's really a placeholder. It means that the standard battery of tests — hormone panels, semen analysis, basic imaging — haven't turned up an obvious cause. It doesn't mean there is no cause. It means the routine workup didn't find one.

According to estimates, unexplained infertility accounts for roughly 10–30% of all infertility diagnoses. That's a significant proportion of people left without a roadmap. And within that group, uterine structural issues — including intrauterine adhesions, polyps, fibroids that distort the cavity, and thin endometrial lining — are among the conditions most likely to have been missed by the tests that were actually done.

Why Asherman's Syndrome Is So Frequently Missed

Asherman's syndrome — characterised by scar tissue (adhesions) that forms inside the uterus, often after a dilation and curettage procedure — is genuinely underdiagnosed. There are a few structural reasons for this, and understanding them is the first step to advocating for yourself.

First, many of its symptoms are subtle or easy to dismiss. As the Cleveland Clinic notes, some cases of Asherman's are entirely asymptomatic — women have no obvious period changes, no pain, nothing that would wave a red flag at a routine appointment. The only sign may be an inability to conceive, or recurrent early pregnancy loss.

Second — and this is the critical part — the tests most commonly used in fertility workups simply don't catch mild to moderate adhesions reliably.

The Tests That Miss It

Transvaginal Ultrasound

A standard transvaginal ultrasound can identify gross structural abnormalities — large fibroids, obvious uterine malformations — but it often fails to detect adhesions, especially mild or filmy ones. Scar tissue inside a collapsed uterine cavity is simply hard to visualise on standard ultrasound. Many women with confirmed Asherman's have had entirely "normal" ultrasound results.

Hysterosalpingogram (HSG)

An HSG is commonly used to check whether the fallopian tubes are open and to get a rough outline of the uterine cavity. It's better than ultrasound for detecting obvious filling defects — but it still misses things. As the American Society for Reproductive Medicine (ASRM) notes, adhesions may appear as "filling defects" on an HSG, but subtle adhesions can be overlooked entirely — particularly if the film quality is poor, the dye fills incompletely, or the adhesions are positioned in a way that the flat X-ray image doesn't capture well. A normal HSG does not rule out Asherman's.

The Test That Does Catch It: Diagnostic Hysteroscopy

This is the conversation I wish I'd had sooner. Diagnostic hysteroscopy — where a thin, lighted camera is passed through the cervix to directly visualise the inside of the uterus — is the gold standard for diagnosing intrauterine adhesions.

There is no other imaging equivalent. Not an MRI, not a saline-infusion sonohysterogram (though that can sometimes suggest adhesions). Only hysteroscopy lets a doctor actually see inside the uterine cavity in real time. The Cleveland Clinic identifies diagnostic hysteroscopy as the primary test for Asherman's syndrome — and the ASRM describes it as "the most accurate" method of diagnosis.

It can be done in an office setting or under general anaesthesia, depending on your doctor and clinical context. If adhesions are found, they can sometimes be treated during the same procedure. But before any of that can happen, you need to ask for it.

Risk Factors: Are You in the Right Group to Ask?

Asherman's syndrome almost always has a history behind it. According to the Cleveland Clinic, over 90% of cases develop after pregnancy-related uterine procedures. If any of the following apply to you, you have a clinical basis for asking your doctor to investigate the uterine cavity more thoroughly:

• One or more D&C procedures (for miscarriage, missed miscarriage, incomplete miscarriage, termination, or retained tissue)
• D&C performed 2–4 weeks after childbirth (e.g., for retained placenta)
• Recurrent miscarriage, especially early or unexplained losses
• Previous hysteroscopic surgery (for fibroids, polyps, septum removal)
• Caesarean section, particularly with complications
• History of endometritis (uterine infection) or pelvic inflammatory disease
• Repeated or multiple uterine procedures
• Difficult or complicated fibroid removal (myomectomy)

The Overlooked Clue: Changes to Your Period

One of the most consistent — and consistently dismissed — symptoms of Asherman's syndrome is a change in menstrual flow. Specifically, periods that have become noticeably lighter, shorter, or sparser since a uterine procedure.

This happens because scar tissue occupies space in the uterine cavity and reduces the amount of endometrial lining that forms and sheds each cycle. As the Cleveland Clinic explains, lighter periods (hypomenorrhea) and absent periods (amenorrhea) are both recognised symptoms — and in some cases, scar tissue blocks blood from exiting altogether, meaning a woman might experience pain but no visible bleeding.

If you've thought to yourself, "my periods have never been the same since that procedure," write that down. Say it out loud at your next appointment. It matters.

Other Uterine Factors Worth Investigating

Even if Asherman's isn't the diagnosis, there are other uterine causes of infertility that are commonly overlooked in standard workups:

• Endometrial polyps: Small, benign growths on the uterine lining that can interfere with implantation. Often asymptomatic and not visible on basic ultrasound without saline infusion.
• Submucosal fibroids: Fibroids that protrude into the uterine cavity can physically disrupt where an embryo implants. Easily missed if cavity mapping wasn't done.
• Thin endometrial lining: A persistently thin endometrium (often under 7mm) can indicate prior uterine damage or poor blood flow, and it compromises implantation regardless of embryo quality.
• Uterine septum: A congenital band of tissue dividing the uterine cavity — associated with recurrent miscarriage and rarely picked up without hysteroscopy or MRI.

All of these fall under the broader category of uterine factor infertility — a term that simply means the uterus itself, structurally, is contributing to the difficulty conceiving or carrying a pregnancy. It's a real category with real solutions. But you can't treat what hasn't been found.

How to Advocate for Yourself with Your Doctor

I want to be direct about this: the medical system moves toward the most common diagnoses first. That is not a criticism of individual doctors — it's just how pattern-based medicine works. Rare or underdiagnosed conditions require patients who know to ask. You are allowed to be that patient.

Here's how to approach the conversation with your OB/GYN or reproductive endocrinologist (RE) without it becoming adversarial:

• Lead with your history. State plainly what procedures you've had and when — "I had a D&C in [year] and since then my periods have been lighter." Give them a timeline.
• Ask specifically about the uterine cavity. "Has the inside of my uterus been directly evaluated?" is a reasonable question. If the answer is no, follow up with why.
• Request or ask about hysteroscopy. You can say, "Given my history, would a diagnostic hysteroscopy be appropriate?" An RE should be willing to discuss this.
• Bring notes. Write down your symptoms and timeline before the appointment. Doctors respond better to documented patterns than to recalled impressions.
• Get a second opinion. If you feel dismissed, seek a second opinion with a reproductive specialist who has experience in uterine cavity disorders. This is not disloyalty. It's due diligence.

Questions to Ask Your Doctor

Print this, screenshot it, or have it open on your phone at your next appointment. These are direct, evidence-based questions that any reproductive specialist should be able to engage with:

1. Has the inside of my uterine cavity been directly visualised — for example, by hysteroscopy? If not, why not given my history?
2. Could my previous D&C (or other uterine procedure) have caused intrauterine adhesions or scarring?
3. Do my period changes since that procedure — lighter flow, shorter duration — indicate anything worth investigating further?
4. Has Asherman's syndrome been considered and actively ruled out, or simply not tested for?
5. What is your experience in diagnosing and treating intrauterine adhesions?
6. Would a sonohysterogram or saline-infusion ultrasound help rule out polyps, adhesions, or other cavity issues before we move forward?
7. If we do find uterine scarring, what does treatment look like and what are the realistic outcomes?
8. Can you refer me to a reproductive endocrinologist or minimally invasive gynaecological surgeon with specific experience in uterine cavity pathology?

If Your Gut Says Something Is Wrong, Listen to It

The "unexplained infertility" label can feel like a dead end. It is not. It is a starting point for a different kind of investigation — one that requires more specificity, more advocacy, and sometimes a different doctor.

Asherman's syndrome is not rare. According to the ASRM, it occurs in a meaningful proportion of women who have had uterine procedures — and treatment, when the diagnosis is found, can significantly improve outcomes. Cleveland Clinic data shows post-treatment pregnancy rates of over 60% in mild cases, with careful monitoring and support. Those numbers matter. But they're only accessible if the diagnosis is made.

Getting that diagnosis starts with a single appointment where you walk in knowing what to ask. That's what the questions above are for. That's what this community is here for.

You're not imagining it. You're not overreacting. And you don't have to accept "unexplained" as a final answer.

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