Fibroid-Associated Infertility

Fibroid associated infertility is difficulty conceiving or maintaining pregnancy in a woman whose only or main finding is one or more uterine fibroids.

• Submucosal fibroids and intramural fibroids that distort the cavity reduce implantation and raise miscarriage risk.
• Fibroids below 4 cm that do not distort the cavity usually do not affect fertility.
• Other causes of infertility must be excluded before surgery.

Failure to conceive after 12 months of regular unprotected intercourse (6 months if aged 35 or over), recurrent miscarriage, heavy periods and pelvic pressure; some women have no symptoms.

• Enlarged irregular uterus.
• Differential diagnosis: anovulation, tubal disease, endometriosis, male factor infertility, intrauterine adhesions, endometrial polyp, adenomyosis.
• Complications: prolonged infertility, miscarriage, preterm birth, repeated surgery and psychological distress.

Diagnosis is by imaging of the cavity, with assessment of ovulation, tubes and semen.

• Pelvic ultrasound with saline infusion sonography or hysteroscopy to define cavity distortion.
• Hysterosalpingography or sonosalpingography for tubal patency.
• Semen analysis for the partner.
• Mid-luteal progesterone, thyroid stimulating hormone and prolactin.
• Anti-Müllerian hormone or antral follicle count; pelvic MRI for planning.

Remove fibroids that distort the cavity, treat other causes of infertility, and refer early for women aged 38 or over.

• Supportive: couple counselling; folic acid 400 micrograms oral daily; weight and lifestyle advice; time intercourse every 2 to 3 days.
• Pharmacological: ovulation induction when anovulatory: letrozole 2.5 mg oral daily on days 3 to 7 of the cycle, increased by 2.5 mg per cycle to 7.5 mg (maximum). Alternative: clomifene citrate 50 mg oral daily on days 2 to 6, increased to 100 mg and then 150 mg (maximum). Leuprorelin 3.75 mg IM every 4 weeks for up to 3 months to shrink fibroids before myomectomy. Anaemia: ferrous sulphate 200 mg oral 8-hourly, continued for 3 months after haemoglobin normalises.
• Procedures: hysteroscopic resection of submucosal fibroids; myomectomy for intramural fibroids that distort the cavity or are above 5 cm, followed by 3 months of waiting before conception; assisted reproduction (intrauterine insemination, in vitro fertilisation) for other causes.
• Special groups: in women aged 38 or over, move early to assisted reproduction. After myomectomy that opened the cavity, deliver by caesarean at 37 to 38 weeks.
• Red flags: rapid fibroid growth, severe pain, suspected sarcoma, repeated miscarriage.
• Follow-up: review at 3 months after surgery; pregnancy attempts for 12 months before further treatment; refer to a fertility specialist if no pregnancy.