GnRH Injection is the Most Appropriate Preoperative Medication
For preoperative fibroid reduction prior to myomectomy, GnRH agonist injection is the most appropriate choice, as it is the only medication proven to significantly reduce fibroid and uterine volume before surgery. 1, 2, 3
Why GnRH Agonists Are Superior for Preoperative Fibroid Reduction
Proven Volume Reduction
- GnRH agonists reduce uterine volume by approximately 175 mL and achieve up to 50% reduction in fibroid volume over 3 months of treatment 2, 3
- This volume reduction is specifically valuable for making surgical myomectomy technically easier with improved visualization and reduced operative complexity 1, 4
- The fibroid shrinkage response can be predicted as early as 4 weeks after the first injection—if a fibroid reduces by 35% at 4 weeks, it will likely achieve 50% reduction by 3 months in 81% of cases 5
Surgical Benefits During Myomectomy
- GnRH pretreatment reduces intraoperative blood loss during myomectomy (ranging from 22-157 mL reduction) 2, 3
- Preoperative hemoglobin levels increase by 0.88 g/dL, which is particularly important if the patient has fibroid-related anemia 2
- Reduced uterine artery blood flow improves surgical vision and reduces bleeding during the procedure 4
Optimal Treatment Protocol
- Administer GnRH agonist for 3-4 months prior to surgery to achieve maximal fibroid volume reduction 1, 2, 3
- Consider adding hormone add-back therapy (low-dose estrogen-progestin) if treatment extends beyond 3 months to prevent bone mineral density loss 6
- Concurrent iron supplementation should be provided to optimize preoperative hemoglobin 7
Why Other Options Are Inappropriate
Combined Contraceptive Pills (Option B)
- Oral contraceptive pills are effective for managing bleeding symptoms but do NOT reduce fibroid size 1, 8
- They are first-line therapy for symptom control in women with small fibroids, not for preoperative volume reduction 1, 7
Intrauterine Contraceptive Device (Option C)
- Levonorgestrel IUDs are the most effective first-line treatment for reducing menstrual blood loss but do NOT shrink fibroids 8, 6, 7
- This option addresses bleeding symptoms only, not surgical preparation 7
Oral Continuous Progesterone Therapy (Option D)
- Progestins may help with bleeding control but lack evidence for significant fibroid volume reduction needed for surgical preparation 1
- They are not recommended as preoperative therapy for myomectomy 1, 6
Important Clinical Caveats
Side Effects to Anticipate
- Hot flushes are significantly more common with GnRH agonists (OR 7.68) compared to placebo, but this is an acceptable trade-off for the surgical benefits 2
- Hypoestrogenic symptoms occur but are temporary and resolve after treatment completion 1, 4
Monitoring Response
- Assess fibroid volume reduction at 4 weeks using ultrasound—if less than 35% reduction is achieved, the final response may be suboptimal and alternative surgical planning may be needed 5
- Doppler ultrasound showing increased uterine artery resistance index at 3 months correlates with successful fibroid shrinkage at 6 months 9