Is deformity of the endometrial cavity from uterine fibroids (leiomyomas) a concerning finding in women of reproductive age?

Is Endometrial Cavity Deformity from Fibroids Concerning?

Yes, deformity of the endometrial cavity from uterine fibroids is a highly concerning finding that significantly impairs fertility outcomes and warrants intervention before attempting conception or assisted reproductive technology. 1, 2

Impact on Reproductive Outcomes

Endometrial cavity distortion from fibroids dramatically reduces fertility success:

• Submucosal fibroids with cavity distortion have the worst outcomes, with pregnancy rates of only 10% and implantation rates of 4.3% in assisted reproduction cycles 1, 2
• Intramural fibroids causing cavity deformation show pregnancy rates of 16.4% and implantation rates of 6.4%, compared to 30.1% and 15.7% respectively in women without fibroids 1, 3
• The miscarriage rate in patients with cavity-distorting fibroids reaches 33.3%, double that of controls at 16.3% 1

Why Cavity Distortion Matters

The mechanism of impaired fertility from cavity deformity involves multiple pathways 1, 4:

• Direct mechanical interference with embryo implantation at the distorted endometrial surface
• Impaired blood supply to the endometrium overlying or adjacent to the fibroid
• Endometrial atrophy and ulceration in areas of cavity distortion
• Altered uterine contractility and increased myometrial rigidity affecting implantation
• Disrupted molecular signaling through excessive extracellular matrix production and altered growth factor availability

Clinical Management Algorithm

For women with cavity-distorting fibroids desiring pregnancy:

1. Submucosal fibroids (protruding into cavity): Hysteroscopic myomectomy is the treatment of choice, achieving pregnancy rates of 85% with live birth rates of 65% 3

2. Intramural fibroids with cavity distortion: Surgical or medical treatment should be considered before attempting assisted reproductive technology 1, 3

   • Laparoscopic or open myomectomy are primary options with similar pregnancy outcomes 3
   • GnRH agonists may be used short-term (2-3 months) to reduce fibroid size before surgery 3

3. Do not proceed with ART until cavity-distorting fibroids are addressed, as outcomes are significantly compromised 1, 3

Diagnostic Confirmation

• Transvaginal ultrasound has 90% sensitivity and 98% specificity for detecting submucosal fibroids and cavity distortion 2
• The cavity should appear as smooth endometrial echoes in an uninterrupted shallow Y contour on ultrasound 1
• MRI is superior when ultrasound findings are equivocal, altering management in up to 28% of patients 2

Critical Distinction

Subserosal fibroids without cavity involvement are NOT concerning for fertility, showing pregnancy rates (34.1%) and implantation rates (15.1%) similar to women without fibroids 1, 3. The location and cavity distortion—not merely fibroid presence—determines clinical significance.

Common Pitfall

Do not assume all fibroids require treatment. Only those causing cavity distortion or submucosal/intramural fibroids affecting the endometrial interface warrant intervention for fertility purposes 1, 3, 5. Unnecessary surgery on subserosal fibroids may cause more harm than benefit through adhesion formation.