Adenomyosis: The Hidden Cause of Heavy Periods and Infertility

Adenomyosis is perhaps the most underrecognised significant gynaecological condition in India. For decades, it was diagnosed only at hysterectomy — when the uterus was sectioned and the characteristic appearance was visible under the microscope. With the advent of high-resolution transvaginal ultrasound and MRI, adenomyosis can now be diagnosed non-invasively — and its recognition as a cause of both heavy, painful periods and fertility failure has grown significantly.

Yet the majority of women with adenomyosis in India are still either undiagnosed or diagnosed late — often after years of managing symptoms as "just bad periods" and, in the fertility context, after multiple failed treatment cycles.

What Is Adenomyosis?

Adenomyosis occurs when endometrial glands and stroma — the tissue that normally lines the inside of the uterus — infiltrate into the myometrium (the muscular wall of the uterus). Unlike endometriosis (where endometrial-like tissue grows outside the uterus), adenomyosis is contained within the uterine wall itself. The two conditions are distinct, but they frequently coexist — approximately 30 to 40% of women with endometriosis also have adenomyosis.

The infiltrating endometrial tissue in adenomyosis responds to hormonal signals just like the normal endometrial lining — thickening and bleeding with each menstrual cycle. Because the blood cannot exit through the cervix, it accumulates within the myometrium, causing local inflammation, progressive fibrosis, and uterine enlargement. The result is a characteristically enlarged, globular, tender uterus — and the symptoms that follow.

Symptoms of Adenomyosis

• Heavy menstrual bleeding (menorrhagia): Often significantly heavy — passing large clots, soaking pads within 1 to 2 hours, requiring iron supplementation for resulting anaemia.
• Severe, cramping period pain (dysmenorrhoea): Often worsening progressively over years, differing from the sharp onset of endometriosis pain — adenomyosis pain tends to build throughout the period.
• Uterine enlargement: The uterus feels diffusely enlarged and may be tender to palpation.
• Pelvic pressure and fullness: A sensation of uterine heaviness, particularly in the premenstrual days.
• Dyspareunia: Deep pain during intercourse, from an enlarged, tender uterus.
• Infertility and IVF failure: Increasingly recognised as a significant cause of both.

Many women with adenomyosis attribute their heavy, painful periods to "just being the way I am" — accepting them as normal when they are not. The average delay from symptom onset to adenomyosis diagnosis in published series is 5 to 10 years.

Diagnosing Adenomyosis

Adenomyosis cannot be diagnosed from symptoms alone — it requires imaging:

• High-resolution transvaginal ultrasound: The first-line investigation. Characteristic features include myometrial thickening (particularly the posterior wall), heterogeneous myometrial echotexture ("Swiss cheese" or "venetian blind" appearance), myometrial cysts, globular uterine enlargement, and asymmetric myometrial thickness. Sensitivity in experienced hands is approximately 80 to 85%.
• MRI: The most accurate non-invasive diagnostic tool for adenomyosis. Shows a thickened junctional zone (the innermost layer of the myometrium, normally below 12 mm) — adenomyosis is diagnosed when junctional zone thickness exceeds 12 mm, with additional features of adenomyotic foci. MRI is particularly useful when ultrasound is equivocal or when detailed mapping is needed before surgery.
• Histology: Definitive diagnosis is histological — endometrial glands and stroma within the myometrium on microscopy. Historically this required hysterectomy; it can now sometimes be obtained from myometrial biopsy samples.

How Adenomyosis Impairs Fertility

The mechanisms through which adenomyosis impairs fertility are multiple:

• Uterine contractility: The adenomyotic myometrium shows abnormal contractility patterns that may impair embryo implantation and transport. Hyperperistaltic uterine movements have been documented in adenomyosis — potentially expelling embryos or sperm before implantation can occur.
• Endometrial receptivity: Adenomyosis alters the molecular environment of the endometrium — inflammatory cytokines, altered pinopode expression, and disrupted uterine natural killer cell activity all impair the implantation window.
• Endometrial blood supply: Abnormal vascularity in adenomyotic uteri may impair endometrial development and implantation.
• Direct mechanical effects: Severe adenomyosis can distort the uterine cavity, functioning similarly to submucosal fibroids in its impact on implantation.

The clinical implications: adenomyosis is increasingly recognised as a cause of unexplained IVF failure — particularly when good-quality embryos fail to implant despite normal endometrial thickness. Women with repeated implantation failure and no other identified cause should have MRI assessment for adenomyosis.

Treatment of Adenomyosis

Medical Suppression

Hormonal suppression reduces adenomyosis activity and provides symptom relief:

• Combined OCP: Continuous use suppresses menstrual cyclicity and reduces symptoms. A reasonable first-line for symptom management in women not trying to conceive.
• Progestogens (dienogest): Increasingly used specifically for adenomyosis — reduces pain and heavy bleeding with continued suppression of adenomyotic tissue.
• Mirena IUS (levonorgestrel intrauterine system): Provides local uterine progestogen release — highly effective for heavy bleeding and pain in adenomyosis, with limited systemic effects. Cannot be used while actively trying to conceive.
• GnRH agonists: Pre-IVF GnRH agonist down-regulation for 2 to 3 months before stimulation is increasingly used in women with adenomyosis undergoing IVF — reducing the inflammatory and contractility burden on the uterus before embryo transfer. Some evidence suggests this improves implantation rates.

Surgical Treatment

Adenomyosis surgery is significantly more challenging than fibroid surgery. Unlike fibroids (which have a clear tissue plane), adenomyotic tissue infiltrates the myometrium without a discrete border — making complete excision difficult without damaging the surrounding myometrium. Options:

• Conservative adenomyomectomy: Excision of focal adenomyotic lesions (adenomyomas) — feasible when the adenomyosis is localised rather than diffuse. Requires meticulous technique; the scar must be carefully repaired.
• Uterine artery embolisation: Cuts blood supply to the uterus, causing adenomyotic tissue to shrink. Primarily for symptom control, not for fertility — fertility rates after UAE are reduced due to impaired endometrial blood supply.
• Hysterectomy: Definitive treatment — curative for adenomyosis. Not appropriate for women who wish to preserve fertility.

Adenomyosis and IVF

The IVF protocol for women with adenomyosis requires modification. Evidence supports:

• GnRH agonist long protocol: 2 to 3 months of GnRH agonist pre-treatment (causing the adenomyosis to be suppressed) before IVF stimulation — may significantly improve implantation rates.
• Freeze-all with deferred FET: Freezing all embryos after stimulation and performing a frozen embryo transfer in a subsequent cycle (when the uterus has had time to recover from stimulation and is in a more receptive state) improves outcomes in adenomyosis.
• Natural cycle FET: Some evidence that natural cycle FET outperforms artificial (hormone replacement) FET in adenomyosis — the corpus luteum may provide beneficial uterine effects.

Frequently Asked Questions

Q1. I was told my uterus looks "bulky" on ultrasound. Does this mean adenomyosis?

A "bulky" uterus on ultrasound report may indicate adenomyosis — but the term alone is not diagnostic. The report should describe myometrial texture and echo pattern, the appearance of the junctional zone, and specific adenomyosis features. If you have symptoms of heavy or painful periods, and the ultrasound shows a bulky uterus with heterogeneous texture, requesting a more detailed evaluation — ideally MRI — is appropriate.

Q2. Can adenomyosis be reversed?

Adenomyosis cannot be fully reversed — the infiltrating endometrial tissue within the myometrium is permanent absent hysterectomy. However, hormonal suppression significantly reduces adenomyosis activity (it is an oestrogen-dependent condition), and symptoms typically improve with suppression. Pre-menopausal women can expect adenomyosis to become clinically inactive after menopause, as oestrogen withdrawal removes the hormonal stimulus.

Q3. I have adenomyosis and have failed 3 IVF cycles. Should I try GnRH agonist pre-treatment?

Yes — this is one of the most important management changes to consider in this situation. Pre-IVF GnRH agonist therapy for 2 to 3 months before stimulation is associated with significantly improved implantation rates in women with adenomyosis in multiple studies. This protocol should be discussed with your IVF specialist before the next cycle.