The contribution of leiomyomas to infertility is difficult to assess because of the high prevalence of uterine leiomyoma in the general population and because the incidence of leiomyomas increases with age, as does infertility. Furthermore, many women with uterine leiomyomas conceive and have uncomplicated pregnancies. Leiomyomas are present in approximately 5-10% of women with infertility and are the sole factor identified in 1-2.4% of women with infertility. However, leiomyomas should not be considered the cause of infertility, or significant component of infertility, without completing a basic fertility evaluation to assess the woman and her partner.
For women with submucous myomas or fibroids that are in the cavity of the uterus, the decision-making is straightforward. Here the evidence is strongest for an affect of fibroids on fertility.
Intramural and submucosal leiomyomas can cause distortion of the uterine cavity or obstruction of the tubal ostia or cervical canal and, thus, may affect fertility or lead to pregnancy complications. When abdominal myomectomies have been performed on women with otherwise unexplained infertility, the subsequent pregnancy rates have been reported to be 40-60% after 1-2 years. Studies of the effect of laparoscopic or hysteroscopic myomectomy on fertility have shown similar results. However, the use of additional fertility treatments may have contributed to these marked positive effects.
Fertility After Myomectomy
Several studies have investigated the effect of leiomyomas on reproductive outcomes after in vitro fertilization (IVF). In the setting of an abnormal, distorted uterine cavity caused by leiomyomas (submucosal or intramural), significantly lower IVF pregnancy rates were identified. In addition, after myomectomy was performed for submucosal leiomyomas, pregnancy rates markedly increased. Subserosal leiomyomas have not been shown to have an impact on reproductive outcomes. However, in the setting of a nondistorted uterine cavity, the impact of intramural leiomyomas on IVF outcomes remains unclear. Intramural, nondistorting leiomyomas may have a subtle impact on IVF outcomes, but there are no definitive data supporting routine prophylactic myomectomy before IVF for women with leiomyomas and normal uterine cavities. It should be noted that most studies included women with leiomyomas of 5 cm or less, and women with larger leiomyomas were often excluded from these studies. Therefore, although leiomyomas that distort the uterine cavity clearly affect reproductive outcomes, further data about leiomyoma size and reproductive outcomes are needed.
Some surgeons believe that a prophylactic myomectomy may be appropriate for select women with large leiomyomas who wish to preserve future fertility. With a skilled surgeon, the evidence demonstrates that the myomectomy complication rate is low even with substantial uterine size; thus, surgery may be reasonable. However, the high risk of recurrent leiomyomas makes this procedure a less effective treatment. Additionally, myomectomy can lead to pelvic adhesive disease, which could cause tubal impairment or obstruction and, hence, infertility.
When assessing a woman with infertility and leiomyomas, targeted evaluation of the uterus and endometrial cavity to assess leiomyoma location, size, and number is indicated. The data suggest that before infertility treatment, surgical treatment for a distorted uterine cavity caused by leiomyomas is indicated. In addition, myomectomy should be considered for a woman with uterine leiomyomas who has undergone several unsuccessful IVF cycles despite appropriate ovarian response and good quality embryos. There are potential adverse effects of nondistorting leiomyomas on IVF outcomes, although these effects are unconfirmed.