How do uterine fibroids affect fertility and what are the treatment options?

Impact of Uterine Fibroids on Fertility and Treatment Options

Intramural and submucosal fibroids significantly impair fertility and should be surgically removed in women desiring pregnancy, while subserosal fibroids generally do not affect fertility and can be left untreated. 1

How Fibroids Affect Fertility

Uterine fibroids (leiomyomas) are extremely common benign tumors affecting up to 80% of women by age 50. Their impact on fertility varies significantly based on their location:

• Submucosal fibroids (SM): Extend into the uterine cavity

  • Most detrimental to fertility
  • Associated with 90% reduction in implantation rates
  • Cause increased risks of spontaneous abortion, preterm delivery, and pregnancy complications 1

• Intramural fibroids (IM): Within the uterine wall

  • Significantly reduce pregnancy rates even without cavity distortion
  • Lower implantation rates (6.4% vs. 15.7% in women without fibroids) 1
  • Mechanism: Impaired gamete transport, reduced blood supply to endometrium, altered endometrial receptivity

• Subserosal fibroids (SS): On the outer surface of uterus

  • Do not significantly impact fertility (pregnancy rates 34.1% vs. 30.1% in women without fibroids) 1
  • Generally do not require removal for fertility purposes 2

Mechanisms of Fertility Impairment

Fibroids can affect fertility through multiple mechanisms:

• Distortion of the endometrial cavity
• Impaired gamete transport
• Decreased endometrial blood supply
• Endometrial inflammation and altered receptivity
• Hormonal environment alterations (estrogen-driven growth) 3

Treatment Options for Women Desiring Pregnancy

1. Hysteroscopic Myomectomy

• Best for: Submucosal fibroids
• Evidence: Improves conception and pregnancy rates in women with otherwise unexplained infertility 2
• Limitations: Ideally for fibroids <5cm, though larger ones can be managed with repeat procedures 2
• Technique: Transcervical removal using electrosurgical wire loop

2. Laparoscopic or Open Myomectomy

• Best for: Intramural fibroids causing symptoms or infertility
• Evidence: Post-myomectomy pregnancy rates of 54-59.5% in women with no other infertility factors 1
• Comparison: Laparoscopic approach offers shorter recovery, less pain, and less febrile morbidity compared to open myomectomy 2
• Considerations: Surgeon expertise crucial, especially for laparoscopic suturing 4
• Limitations: Generally recommended for <3 fibroids of 5cm or a single fibroid <15cm 4

3. Uterine Artery Embolization (UAE)

• Generally not recommended as first-line for women desiring pregnancy 2
• Concerns: Higher miscarriage rates, adverse pregnancy outcomes, and potential impact on ovarian reserve 2
• Recent evidence: Some newer studies show promising fertility outcomes with live birth rates of 73-81% following UAE 1
• Controversy: Earlier studies showed higher miscarriage rates after UAE compared to myomectomy, but recent data suggests comparable outcomes 1

4. Medical Therapy

• Limited role in women actively pursuing pregnancy
• Reason: Most medications suppress ovulation or disrupt endometrial development 2
• GnRH agonists/antagonists: Effective at reducing fibroid volume but cause hypoestrogenic side effects 3
• Selective Progesterone Receptor Modulators (SPRMs): Promising but some have hepatotoxicity concerns 3

Treatment Algorithm for Fertility-Preserving Management

1. Diagnostic evaluation:

   • Transvaginal ultrasound, hysteroscopy, or MRI to classify fibroids by location and size
   • Assess cavity distortion and degree of myometrial invasion

2. Management based on fibroid type:

   • Submucosal fibroids: Hysteroscopic myomectomy regardless of symptoms
   • Intramural fibroids: Laparoscopic or open myomectomy if symptomatic
   • Subserosal fibroids: No intervention needed unless causing symptoms

3. Special considerations:

   • Use anterior uterine incisions during abdominal myomectomy to minimize adhesions
   • Consider pre-operative assessment of submucosal fibroids with combination of hysteroscopy and transvaginal ultrasound
   • Avoid UAE in women desiring pregnancy unless other options exhausted

Important Caveats

• Hysterosalpingogram is not appropriate for evaluating fibroids 2
• Estrogen exposure (including topical) may increase fibroid growth and should be monitored 3
• Medical therapy alone is not recommended for fertility treatment 2
• Removal of subserosal fibroids is generally not recommended for fertility purposes 2

For women who have completed childbearing, additional options include hysterectomy, endometrial ablation, and UAE, which provide definitive symptom relief but are not compatible with future fertility.