Gynecology

Biology & Causes: How Uterine Scarring Happens

At a Glance

Asherman syndrome occurs when the deep foundational layer of the uterine lining is damaged, usually from a surgical procedure like a D&C. This trauma triggers chronic inflammation, prompting the uterus to build tough scar tissue (adhesions) instead of healthy lining.

To understand Asherman syndrome, it helps to think of the uterine lining (endometrium) as a garden with two layers of soil. The top layer (the functionalis) is what grows and sheds every month during your period ^[1]. The bottom layer (the basalis) is the permanent foundation that contains the “seeds” or stem cells needed to regrow the top layer ^[1]^[2]. Asherman syndrome happens when this foundation is damaged, causing the uterus to grow scar tissue instead of healthy lining ^[3]^[4].

The Trigger: Trauma to the Foundation

Asherman syndrome is almost always caused by physical trauma to the uterine wall. When the bottom layer (the basalis) is scraped or injured, the “seeds” for regeneration are lost ^[3]^[5]. This most commonly occurs during:

Dilation and Curettage (D&C): A procedure to clear the uterus after a miscarriage or birth. If performed “blindly” (without a camera), there is a higher risk of accidentally scraping the basal layer ^[6]^[7]. Note: The vast majority of D&Cs heal perfectly normally and do not cause Asherman syndrome, especially when performed with ultrasound guidance.
Postpartum Hemorrhage Care: The uterus is particularly soft and vulnerable shortly after childbirth, making the basal layer easier to damage during medical interventions ^[3].
Uterine Surgeries: Procedures like a myomectomy (fibroid removal) can also create deep enough wounds to trigger scarring ^[3].

When Healing Goes Wrong

In a healthy uterus, the body repairs minor injuries by growing new, flexible tissue. In Asherman syndrome, the body switches from “repair mode” to “scar mode.” This is driven by several biological factors:

Chronic Inflammation

After an injury, the body sends “emergency” immune cells to the area. In Asherman syndrome, these cells stay too long and release constant distress signals ^[8]^[9]. This constant state of alarm tells the body to keep building tough, fibrous tissue rather than soft, healthy lining ^[9].

A Cellular Identity Crisis

One of the most complex parts of this process is a cellular identity crisis where normal cells forget their purpose ^[10].

Normally, the cells lining your uterine blood vessels have a specific job: helping blood flow and nutrients reach the lining.
In response to severe trauma and inflammation, these cells lose their identity ^[11]^[12].
They transform into myofibroblasts—cells that act like construction workers whose only job is to pump out collagen, the main ingredient in scar tissue ^[13]^[14].

From Lining to Adhesions

As these myofibroblasts take over, they fill the uterine cavity with tough, non-functional fibers. Because the uterus is a flat, muscular organ, these scars often act like glue, causing the front and back walls of the uterus to stick together (adhesions) ^[15]^[16]. Once this bridge of scar tissue forms, the healthy lining can no longer grow over it, leading to the symptoms of light or absent periods ^[4]^[16].

Modern research is currently focused on how to “reset” this environment—using stem cell therapies or growth factors to convince the uterus to stop making scars and start regrowing the foundation ^[17]^[18].

Common questions in this guide

What causes Asherman syndrome?

Asherman syndrome is almost always caused by physical trauma to the deep layer of the uterine wall. This usually happens during procedures like a D&C, fibroid removal, or treatment for postpartum bleeding, which can damage the cells needed to regrow the uterine lining.

Why does a D&C sometimes cause uterine scarring?

If a D&C is performed without a camera or ultrasound guidance, there is a risk of accidentally scraping the deep basal layer of the uterus. When this foundation is damaged, the body may heal by forming scar tissue instead of regrowing a healthy lining.

How does inflammation lead to intrauterine adhesions?

After a uterine injury, chronic inflammation can cause immune cells to stay in the area too long. This constant state of alarm triggers cells to produce tough, fibrous collagen, creating scar tissue that glues the front and back walls of the uterus together.

Can my uterine lining regrow if I have Asherman syndrome?

Regrowing the lining depends on how much of your foundational layer remains intact. Doctors often use a combination of scar removal, barrier gels like hyaluronic acid to prevent new scars, and estrogen protocols to encourage your healthy lining to regrow.

Curated prompts to bring to your next appointment.

1.How much of my basal layer remains intact according to my ultrasound or hysteroscopy results?
2.Would you recommend using hyaluronic acid gel or other barrier agents to prevent further fibrosis after my procedure?
3.Do you suspect that chronic inflammation or an undetected infection played a role in my scarring?
4.What is your protocol for using estrogen to help my healthy lining (the functionalis layer) regrow?

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References (18)

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This information explains the biology and causes of Asherman syndrome for educational purposes only. Always consult your gynecologist or reproductive specialist regarding your specific symptoms or surgical history.

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