The incidence of uterine Leiomyoma among subfertile women without any other cause for subfertility is 1-2.4%. Fibroids cause uterine cavity distortion by physical infringement. There is a lack of reliable data, but large myomas compromising the uterine cavity can interfere with implantation due to vascular compromise, secretion of vasoactive substances, endometrial inflammation or disordered placentation. There is increasing evidence that intramural fibroids affect implantation even when there is no cavity compromise and a study found that fibroids of <5 cm in diameter reduced continuing pregnancy rates by half following assisted conception (Dubuisson 2000).
A systematic review of 11 observational studies suggests that women with submucous myoma have lower pregnancy rates compared with women with other causes for their subfertility (relative risk [RR] 0.30, 95% CI 0.13 to 0.70) (Pritts 2001, NICE 2013).
Myomectomy was not associated with an increase in live birth rate (RR 0.98, 95% CI 0.45 to 2.41) but was associated with a higher pregnancy rate (RR 1.72, 95% CI 1.13 to 2.58), [Evidence level 2b]. Women with intramural uterine fibroids had a reduced chance of pregnancy when compared with women with no fibroids following assisted reproduction (OR 0.46, 95% CI 0.24 to 0.88),[Evidence level 2b] (NICE 2013, Virkauf 1992).
The pregnancy rate in women following myomectomy was higher than that in women with untreated myoma (42% versus 25%), [Evidence level 3] (NICE 2013).
A RCT that compared different surgical methods for undertaking myomectomy (abdominal myomectomy versus laparoscopic myomectomy) found no differences in pregnancy rates or miscarriage rates. There was significantly higher incidence of postoperative fever and a drop in haemoglobin and hospital stay in the group following abdominal myomectomy [Evidence level 1b] (Seracchioli 2000, NICE 2013).
Myomectomy is a major procedure with potential risks to the integrity and the viability of the uterus. Furthermore, there is the potential for major blood loss during surgery, which can be offset by preoperative treatment with gonadotrophin releasing hormone agonist for 6–8 weeks, which will cause significant shrinkage with reduced vascularity of the fibroids. Hysteroscopic resection is preferable for small submucous fibroids, although it is important to accurately assess the ratio of intracavitary to intramural proportions of the myoma before making a surgical plan. The place of less-invasive procedures, such as uterine artery embolisation (UAE) and magnetic resonance guided laser coagulative necrosis (MrGFUS) or high-intensity focused ultrasound for the destruction of fibroids in the context of subfertility is still being evaluated, although some studies show promising results (Bradley et al 2009). In essence benefit surgical treatment of uterine abnormalities to enhance pregnancy rates is not yet established by randomised controlled trials (NICE 2013).
Bradley LD, Falcone T, editors. Hysteroscopy – Office Evaluation and Management of the Uterine Cavity. Mosby; Elsevier; 2009.
Seracchioli R, Rossi S, Govoni F, Rossi E, Venturoli S, Bulletti C, et al. Fertility and obstetric outcome after laparoscopic myomectomy of large myomata: a randomized comparison with abdominal myomectomy. Hum Reprod 2000;15:2663–8.