Two chronic gynecologic conditions notably affect a woman’s quality of life (QoL), including fertility – one is endometriosis, and the other is a fibroid uterus. For a benign tumor, fibroids have an impressive prevalence found in approximately 50%-60% of women during their reproductive years. By menopause, it is estimated that 70% of woman have a fibroid, yet the true incidence is unknown given that only 25% of women experience symptoms bothersome enough to warrant intervention. This month’s article reviews the burden of fibroids and the latest management options that may potentially avoid surgery.
Background
Fibroids are monoclonal tumors of uterine smooth muscle that originate from the myometrium. Risk factors include family history, being premenopausal, increasing time since last delivery, obesity, and hypertension (ACOG Practice Bulletin no. 228 Jun 2021: Obstet Gynecol. 2021 Jun 1;137[6]:e100-e15) but oral hormonal contraception, depot medroxyprogesterone acetate (MPA), and increased parity reduce the risk of fibroids. Compared with White women, Black women have a 2-3 times higher prevalence of fibroids, develop them at a younger age, and present with larger fibroids.
The FIGO leiomyoma classification is the agreed upon system for identifying fibroid location. Symptoms are all too familiar to gynecologists, with life-threatening hemorrhage with severe anemia being the most feared, particularly for FIGO types 1-5. Transvaginal ultrasound is the simplest imaging tool for evaluation.
Adapted from Int J Gynecol Obstet. 2011;113:3-13.
This chart illustrates the International Federation of Gynecology and Obstetrics (FIGO) classification system for fibroid location.
Fibroids and fertility
Fibroids can impair fertility in several ways: alteration of local anatomy, including the detrimental effects of abnormal uterine bleeding; functional changes by increasing uterine contractions and impairing endometrium and myometrial blood supply; and changes to the local hormonal environment that could impair egg/sperm transport, or embryo implantation (Hum Reprod Update. 2017;22:665-86).
Prior to consideration of surgery, saline infusion sonogram can determine the degree of impact on the endometrium, which is most applicable to the infertility patient, but can also allow guidance toward the appropriate surgical approach.
Treatment options – medical
Management of fibroids is based on a woman’s age, desire for fertility, symptoms, and location of the fibroid(s). Expectant observation of a woman with fibroids may be a reasonable approach, provided the lack of symptoms impairing QoL and of anemia. Typically, there is no change in fibroid size during the short term, considered less than 1 year. Regarding fertility, studies are heterogeneous so there is no definitive conclusion that fibroids impair natural fertility (Reprod Biomed Online. 2021;43:100-10). Spontaneous regression, defined by a reduction in fibroid volume of greater than 20%, has been noted to occur in 7.0% of fibroids (Curr Obstet Gynecol Rep. 2018;7[3]:117-21).
When fertility is not desired, medical management of fibroids is the initial conservative approach. GnRH agonists have been utilized for temporary relief of menometrorrhagia because of fibroids and to reduce their volume, particularly preoperatively. However, extended treatment can induce bone mineral density loss. Add-back therapy (tibolone, raloxifene, estriol, and ipriflavone) is of value in reducing bone loss while MPA and tibolone may manage vasomotor symptoms. More recently, the use of a GnRH antagonist (elagolix) along with add-back therapy has been approved for up to 24 months by the Food and Drug Administration and has demonstrated a more than 50% amenorrhea rate at 12 months (Obstet Gynecol. 2020;135:1313-26).
Dr. Mark P. Trolice
Progesterone plays an important role in fibroid growth, but the mechanism is unclear. Although not FDA approved, selective progesterone receptor modulators (SPRM) act directly on fibroid size reduction at the level of the pituitary to induce amenorrhea through inhibition of ovulation. Also, more than one course of SPRMs can provide benefit for bleeding control and volume reduction. The SPRM ulipristal acetate for four courses of 3 months demonstrated 73.5% of patients experienced a fibroid volume reduction of greater than 25% and were amenorrheic (Fertil Steril. 2017;108:416-25). GnRH agonists or SPRMs may benefit women if the fibroid is larger than 3 cm or anemia exists, thereby precluding immediate surgery.
Other medication options include the levonorgestrel IUD, combined hormonal contraceptives, and tranexamic acid – all of which have limited data on effective results of treating abnormal uterine bleeding.