What are the treatment options for pregnant women with fibroids (uterine leiomyomas) to improve pregnancy outcomes?

Treatment Options for Pregnant Women with Fibroids to Improve Pregnancy Outcomes

Laparoscopic or open myomectomy is the preferred treatment for pregnant women with fibroids experiencing reproductive dysfunction, particularly for intramural fibroids causing symptoms or infertility. 1, 2

Impact of Fibroids on Pregnancy

Uterine fibroids (leiomyomas) can significantly impact fertility and pregnancy outcomes, with effects varying based on their location:

• Submucosal fibroids: Most detrimental to fertility, associated with a 90% reduction in implantation rates and increased risks of spontaneous abortion, preterm delivery, and pregnancy complications 2
• Intramural fibroids: Significantly reduce pregnancy rates even without cavity distortion, with lower implantation rates (6.4% vs. 15.7% in women without fibroids) 2
• Subserosal fibroids: Generally do not significantly impact fertility 2

Treatment Options Based on Fibroid Type

For Submucosal Fibroids

• Hysteroscopic myomectomy: First-line treatment for submucosal fibroids 1, 2
  • Improves conception and pregnancy rates in women with otherwise unexplained infertility
  • Best results for fibroids <5cm
  • Retrospective studies show pregnancy rates of 85% after hysteroscopic myomectomy with live birth rates of 65% 1
  • However, high-quality evidence on live birth rates is lacking, with miscarriage rates reported between 30-50% in some studies 1

For Intramural Fibroids

• Laparoscopic or open myomectomy: Recommended for intramural fibroids causing symptoms or infertility 1, 2
  • Post-myomectomy pregnancy rates of 54-59.5% in women with no other infertility factors
  • Generally recommended for <3 fibroids of 5cm or a single fibroid <15cm
  • Similar pregnancy and live birth rates between laparoscopic and open approaches
  • Miscarriage rate comparable to general population at 14% 1
  • Laparoscopic approach associated with decreased postoperative fever, shorter hospital stays, and smaller decrease in postoperative hemoglobin 1

Medical Management Options

• Ulipristal acetate (Selective Progesterone Receptor Modulator):

  • Shown to reduce fibroid volume by 41% in patients with infertility and submucosal fibroids undergoing IVF 1
  • Pregnancy rates similar to matched controls without fibroids 1
  • Can be administered intermittently, allowing for menstruation during medication breaks 2

• GnRH agonists/antagonists:

  • Effective at reducing fibroid volume 2
  • Primarily used for short courses to decrease fibroid size before surgery 1
  • Associated with hypoestrogenic effects including headaches, hot flushes, hypertension, and loss of bone mineral density 1

Alternative Treatments

• Uterine Artery Embolization (UAE):

  • May be considered for women desiring pregnancy 1, 2
  • Recent evidence shows promising fertility outcomes with live birth rates of 73-81% following UAE 2
  • One retrospective study showed spontaneous pregnancy rates of 29.5% and 40.1% at 1 and 2 years following UAE, with a live birth rate of 81% 1
  • However, not generally recommended as first-line treatment due to concerns about higher miscarriage rates and adverse pregnancy outcomes 2

• MR-Guided Focused Ultrasound (MRgFUS):

  • Evidence for fertility enhancement is limited to case reports 1
  • A randomized controlled trial to investigate efficacy and safety was terminated due to lack of enrollment 1

Treatment Algorithm for Pregnant Women with Fibroids

1. Determine fibroid location and size using transvaginal ultrasound, hysteroscopy, or MRI 2

2. For submucosal fibroids:

   • Proceed with hysteroscopic myomectomy if fibroids are <5cm
   • Consider medical management with ulipristal acetate if planning IVF

3. For intramural fibroids:

   • Laparoscopic or open myomectomy is preferred
   • Laparoscopic approach when possible (fewer complications, shorter recovery)
   • Open approach for multiple fibroids or very large uteri

4. For subserosal fibroids:

   • No intervention needed unless causing significant symptoms 2

5. For women with fibroids during pregnancy:

   • Additional fetal surveillance when placenta is implanted over or in close proximity to a fibroid 3
   • Myomectomy during pregnancy is not recommended except in women who have experienced previous pregnancy complications related to these fibroids 3

Cautions and Considerations

• Hysterectomy is not appropriate for women desiring pregnancy 1
• Endometrial ablation is associated with high risk of pregnancy complications and should be avoided 1
• Case reports have associated laparoscopic and open myomectomy with uterine rupture during subsequent pregnancy 1
• Most medical therapies suppress fertility during treatment, making them less suitable for women actively trying to conceive 1

By following this treatment algorithm based on fibroid type and location, clinicians can optimize pregnancy outcomes in women with uterine fibroids while preserving fertility.