Ultrasound assessment of the uterine cavity: endometrial polyps, submucosal fibroids, thickened endometrium, adhesions and uterine septum

01What is the uterine cavity and what can affect it?

The uterine cavity is the space inside the womb, lined by a layer called the endometrium. This is where an embryo implants and where menstrual blood comes from. Any change in the shape of the cavity or the thickness of the endometrium can cause irregular bleeding, difficulty getting pregnant or miscarriage.

The most common uterine-cavity conditions are:

• Endometrial polyps: small, usually benign overgrowths of the endometrium.
• Submucosal fibroids: fibroids that grow towards the inside of the womb and distort the cavity.
• Thickened endometrium (simple thickening or endometrial hyperplasia): a lining thicker than expected for your age and cycle phase.
• Intrauterine adhesions (synechiae, Asherman’s syndrome): bands of scar tissue joining the walls of the womb, often after a D&C (curettage).
• Congenital anomalies: septate, bicornuate, arcuate or unicornuate uterus.
• Retained tissue: pregnancy tissue left behind after miscarriage, birth or termination.

FIGO (the International Federation of Gynecology and Obstetrics) groups the structural causes of abnormal uterine bleeding under the acronym PALM: Polyp, Adenomyosis, Leiomyoma (fibroid) and Malignancy/hyperplasia. Three of these four can be assessed first with ultrasound.

02Which symptoms mean you should have a uterine ultrasound?

You should have a gynaecological ultrasound focused on the uterine cavity if you have any of these symptoms or situations:

• Bleeding between periods or after sex (spotting outside your cycle).
• Very heavy periods, with clots, or long periods (more than 7–8 days).
• Irregular cycles that change suddenly.
• Bleeding after the menopause, even a small spot.
• Difficulty getting pregnant for 12 months, or 6 months if you are over 35.
• Two or more miscarriages, especially late miscarriages.
• Very light or absent periods after a D&C.
• Persistent bleeding, pain or fever after a miscarriage or birth.
• Before starting IVF or intrauterine insemination (IUI), to confirm the cavity is normal.
• Regular review if you take tamoxifen or hormone replacement therapy.

Many small polyps and fibroids cause no symptoms at all and are found by chance. That is why a cavity assessment is a standard part of investigating a couple with infertility.

03What are endometrial polyps and are they cancer?

Endometrial polyps are localised overgrowths of the endometrium that project into the uterine cavity, like a small finger or droplet of tissue. There may be one or several, from a few millimetres to several centimetres. The vast majority are benign (not cancer).

Symptoms of uterine polyps:

• Bleeding or spotting between periods.
• Heavier or longer periods.
• Bleeding after sex.
• Bleeding after the menopause.
• Difficulty getting pregnant.
• Often no symptoms at all.

Can a polyp be cancer? The risk is low but not zero, and depends mainly on age and menopausal status. A meta-analysis of 51 studies including 35,345 women (Uglietti et al., Menopause, 2019) found malignancy in 2.73% of polyps: 1.12% in premenopausal women and 4.93% in postmenopausal women. The risk is highest when a polyp comes with postmenopausal bleeding.

On ultrasound a polyp usually looks like a round or oval structure, brighter (hyperechoic) than the surrounding endometrium, often with a single feeding vessel visible on colour Doppler (the “pedicle artery sign“ in IETA consensus terminology). The doctor will advise if additional imaging such as 3D or saline-contrast ultrasound, or hysteroscopy, is needed to confirm and remove it.

Small polyps without symptoms in younger women are sometimes simply monitored, because some regress on their own. Symptomatic polyps, polyps after the menopause and polyps in women trying to conceive are usually removed hysteroscopically (hysteroscopic polypectomy).

04Fibroids in the uterus: what is a submucosal fibroid and how is it found?

A fibroid (myoma, leiomyoma) is a benign tumour of the muscle of the womb. Fibroids are very common: in the study by Baird et al. (American Journal of Obstetrics and Gynecology, 2003), by age 50 around 70% of white women and more than 80% of black women had fibroids on ultrasound. Most never cause problems.

What matters is location. The FIGO classification divides fibroids into types 0–8:

• Type 0: entirely inside the cavity, attached by a stalk (pedunculated).
• Type 1: more than half of the fibroid is inside the cavity.
• Type 2: less than half is inside the cavity, the rest in the wall of the womb.
• Types 3–8: intramural (in the wall), subserosal (on the outer surface) or other fibroids that usually do not distort the cavity.

Submucosal fibroids (types 0–2) are the ones that affect the cavity most. Typical symptoms are very heavy periods, anaemia from blood loss, long periods, pain and difficulty conceiving.

A transvaginal ultrasound shows the number, size and position of each fibroid and how much it distorts the cavity. This measurement is decisive because it determines whether the fibroid can be removed hysteroscopically (without incisions, from inside the womb) or needs another approach. For type 2 fibroids, or when the margins are unclear, the doctor may advise additional imaging or a diagnostic hysteroscopy.

05Thickened endometrium: what is a normal endometrial thickness?

Endometrial thickness changes through the menstrual cycle, so “thick“ only makes sense in relation to your age and cycle phase. In women of reproductive age the endometrium is thin just after a period, thickens gradually until ovulation and reaches its highest values in the second half of the cycle. A single measurement without the cycle day can therefore be misleading.

After the menopause it is different. According to ACOG (the American College of Obstetricians and Gynecologists, Committee Opinion No. 734, 2018), in a woman with postmenopausal bleeding an endometrial thickness of 4 mm or less on transvaginal ultrasound has a negative predictive value above 99% for endometrial cancer. Above this threshold, or when the endometrium cannot be seen clearly, further assessment is needed (endometrial biopsy or hysteroscopy).

Causes of a thickened endometrium:

• Oestrogen exposure without progesterone (cycles without ovulation, polycystic ovary syndrome, obesity).
• Polyps hidden within a thick lining.
• Endometrial hyperplasia, with or without atypia.
• Hormone replacement therapy or tamoxifen.
• Less commonly, endometrial cancer.

A thick endometrium does not mean cancer. But when it comes with postmenopausal bleeding, or with irregular bleeding after age 45, it should always be investigated.

06Intrauterine adhesions (Asherman’s syndrome) and retained tissue after miscarriage: what does ultrasound show?

Intrauterine adhesions (synechiae) are bands of scar tissue that stick the walls of the cavity together. When they cause very light or absent periods, infertility or miscarriage, the condition is called Asherman’s syndrome.

The main cause is injury to the endometrium after pregnancy, especially a D&C (curettage) after miscarriage or birth. A meta-analysis (Hooker et al., Human Reproduction Update, 2014) found adhesions in 19.1% of women examined by hysteroscopy within a year of a miscarriage, with a higher risk after repeated curettage.

On ultrasound, adhesions may appear as interruptions of the endometrial line, areas where the lining is very thin, or bridges across the cavity. Ultrasound gives useful clues, but hysteroscopy is the method that confirms and treats adhesions.

Retained products of conception are placental or pregnancy tissue left in the womb after a miscarriage (spontaneous or medically managed), birth or termination. Signs include:

• Bleeding that continues or restarts weeks after a miscarriage or birth.
• Lower abdominal pain.
• Offensive discharge or fever (signs of infection that need urgent review).

Transvaginal ultrasound with colour Doppler is the first-line test: it distinguishes simple blood clots from retained tissue with a blood supply. This helps keep treatment as gentle on the endometrium as possible, which lowers the risk of future adhesions.

07Septate uterus and congenital uterine anomalies: when do they matter?

Congenital uterine anomalies form before birth, when the womb develops from the fusion of two halves. According to a systematic review of 94 studies including 89,861 women (Chan et al., Human Reproduction Update, 2011), they are found in about 5.5% of women in the general population, 8.0% of infertile women, 13.3% of women with a history of miscarriage and 24.5% of women with both miscarriage and infertility.

The main types under the ESHRE/ESGE classification:

• Septate uterus: a wall of tissue divides the cavity partly or completely. It is the most common anomaly in women with miscarriage or infertility.
• Bicornuate uterus: the womb has two “horns“ and its outer surface is indented.
• Arcuate uterus: a slight dip in the roof of the cavity, usually of no clinical significance.
• Unicornuate or didelphys uterus: development of only one half, or two separate wombs.

Telling a septate uterus from a bicornuate uterus matters because treatment is completely different. This requires seeing both the cavity and the outer contour of the womb at the same time. The ESHRE/ESGE consensus recommends 3D ultrasound as the main method for diagnosing congenital anomalies. After the standard scan, the doctor will advise whether 3D ultrasound, saline-contrast ultrasound or hysteroscopy is needed.

Does a septum need surgery? Not always. The randomised TRUST trial (Rikken et al., Human Reproduction, 2021) found no improvement in live births after hysteroscopic septum resection compared with expectant management. The decision is individual, based on miscarriage and fertility history and the size of the septum.

08How is a uterine-cavity ultrasound done and on which day of the cycle?

A uterine-cavity ultrasound is a gynaecological scan, mainly transvaginal, using a slim probe placed in the vagina with a hygienic cover and gel. This route gives much clearer images of the endometrium than a scan through the abdomen. For women who have never had sexual intercourse, an abdominal scan or an alternative route is used, as advised by the doctor.

Best day of the cycle: just after your period ends, around cycle day 5–10. At this stage the endometrium is thin and polyps, submucosal fibroids and adhesions are easiest to see. For some questions, such as the cavity shape in congenital anomalies, the doctor may ask for a scan in the second half of the cycle. After the menopause the scan can be done on any day. If you have active bleeding and worrying symptoms, do not wait for the ideal day: call the clinic.

Step by step at Klinika Gjata:

1. Book by phone on +355 4 234 0059 and give your cycle day or the date of your last period.
2. Bring previous scans, blood tests, hysteroscopy or operation reports and a list of your medicines.
3. The doctor asks about your symptoms, cycle, pregnancies, miscarriages and any previous D&C.
4. For a transvaginal scan you empty your bladder; a full bladder is not needed.
5. The scan is performed on a GE Voluson system, measuring endometrial thickness and assessing the cavity, any fibroids and the ovaries, with colour Doppler when needed.
6. Assoc. Prof. Dr. Elinda Gjata performs and interprets the scan herself, with no intermediary.
7. The findings are explained immediately, with images, and you receive a recommendation for the next step: monitoring, treatment, further imaging or hysteroscopy.

The examination is usually painless. You may feel slight pressure. You can return to normal activities straight afterwards.

09Do polyps, fibroids and a septum affect pregnancy, IVF and miscarriage?

Yes, uterine-cavity conditions can lower the chance of pregnancy and raise the risk of miscarriage, because they interfere with how the embryo implants or is nourished. The size of the effect depends on the type, size and position of the problem.

What studies show:

• Polyps: in a randomised trial of 215 infertile women undergoing insemination (Pérez-Medina et al., Human Reproduction, 2005), pregnancy was about twice as common after hysteroscopic polyp removal (about 63% versus 28%). Cochrane rates this evidence as low quality because it rests on a single trial.
• Submucosal fibroids: the meta-analysis by Pritts et al. (Fertility and Sterility, 2009) showed that fibroids distorting the cavity reduce clinical pregnancy, implantation and live birth, and increase miscarriage. A multicentre cohort study (Ultrasound in Obstetrics & Gynecology) linked an isolated submucosal fibroid with about 4.7 times higher odds of late miscarriage.
• Adhesions: reduce the area of functioning endometrium and are linked to infertility and recurrent miscarriage.
• Septum: linked to miscarriage and preterm birth, but removing it does not always bring benefit (TRUST trial, 2021).

Before IVF: most centres check the uterine cavity before embryo transfer. If the scan shows a polyp, submucosal fibroid or adhesions, treatment before transfer is usually advised so the embryo has the best possible environment. As an infertility specialist, Dr. Gjata assesses the cavity as part of the couple’s full plan, not as a stand-alone test.

Polyps and pregnancy: if a polyp is found during pregnancy it is usually not removed; most decisions are made after the birth. Fibroids and pregnancy: most women with fibroids have normal pregnancies, but submucosal and large fibroids need closer follow-up.

10Bleeding after the menopause: why do you need an ultrasound without delay?

Any bleeding after the menopause, even a single spot, should be checked without delay, because it is the main symptom of endometrial cancer. In most cases the cause is benign (endometrial atrophy, a polyp), but that can only be said after assessment.

The menopause is defined as 12 months without a period. Bleeding after that is not “a period coming back“. The UK NICE guideline NG12 recommends that women aged 55 and over with postmenopausal bleeding are referred on the suspected-cancer pathway.

What happens:

1. A transvaginal ultrasound to measure endometrial thickness and look for polyps or masses.
2. If the endometrium is 4 mm or thinner and the bleeding does not recur, the risk of cancer is very low (ACOG, 2018).
3. If the endometrium is thicker, cannot be seen clearly or a polyp is present, an endometrial biopsy or hysteroscopy is needed.
4. If bleeding recurs even with a thin endometrium, assessment continues.

If you take tamoxifen or hormone replacement therapy, the thresholds change and interpretation requires experience: tell the doctor about every medicine you take.

11What happens after the scan: results and when is hysteroscopy needed?

After the scan the doctor explains what she saw and what it means for you. Possible next steps are:

• Normal cavity: nothing further, or routine review.
• Small finding without symptoms: a repeat scan after one or more cycles, on the right cycle day.
• Unclear finding: the doctor will advise if additional imaging such as 3D or saline-contrast ultrasound, or a diagnostic hysteroscopy, is needed.
• Polyp, submucosal fibroid, adhesions or septum needing treatment: referral for operative hysteroscopy.
• Thickened endometrium with risk factors: endometrial biopsy or hysteroscopy with biopsy.

Hysteroscopy is an examination in which a thin camera is passed through the cervix into the cavity, with no cut on the abdomen. It lets the doctor see the inside of the womb directly and, at the same time, remove polyps (hysteroscopic polypectomy), submucosal fibroids (hysteroscopic myomectomy), adhesions or a septum. The tissue removed is sent for histological examination.

Assoc. Prof. Dr. Elinda Gjata trained in colposcopy and hysteroscopy in Paris (Hôpital Tenon and Clinique d’Alma, 2006). Surgical procedures such as hysteroscopic polypectomy and myomectomy are carried out in partnership with private hospitals, while follow-up before and after the procedure takes place at the clinic.

When to call straight away: very heavy bleeding (soaking a pad an hour for several hours), dizziness, severe pain or fever.

12Why Klinika Gjata in Tirana, and what does the cost of the scan depend on?

Klinika Gjata, on Rruga Hasan Sufa in Tirana, has been running since 2009 and is led by Assoc. Prof. Dr. Elinda Gjata, MD, Dr. Sc., an obstetrician-gynaecologist and infertility specialist with more than 25 years’ experience and Associate Professor at the University of Medicine, Tirana.

What you get:

• A scan performed and interpreted by the doctor herself, not by a technician.
• Ultrasound training at the Ian Donald School of Ultrasound.
• Training in colposcopy and hysteroscopy in Paris (Hôpital Tenon / Clinique d’Alma, 2006), so the scan is read with the follow-on treatment in mind.
• A GE Voluson ultrasound system for detailed gynaecological imaging.
• Specific infertility experience: the cavity assessment is linked to your full plan for pregnancy, IUI or IVF.
• Continuity: the same doctor follows you from the scan to the procedure and the check-up afterwards.

What the cost depends on: the price depends on the type of visit (first visit or follow-up), whether the scan is done alone or with a full gynaecology or fertility consultation, the need for Doppler or repeat scans in different cycles, and whether a biopsy, hysteroscopy or hospital procedure is needed afterwards. For accurate information, call the clinic on +355 4 234 0059.