Dr Morin is a Fellow in Reproductive Endocrinology and Infertility at Thomas Jefferson University/Reproductive Medicine Associates of New Jersey in Basking Ridge, New Jersey. He has no conflicts of interest to report in respect to the content of this article.
Dr Schlaff is Professor and Chair of the Department of Obstetrics & Gynecology at Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia, Pennsylvania. He reports performing contracted research for AbbVie Pharmaceuticals.
Fibroids are extremely common in women of reproductive age. One large study reported that 70% of Caucasian and 80% of African-American women had at least one ultrasound- or pathology-confirmed fibroid by the end of their reproductive years.1 While many of these women experience no negative effects of fibroids on their reproductive function, a significant number are at increased risk of infertility, miscarriage, or poor obstetric outcomes. As a result, the average ob/gyn is confronted with a variety of clinical scenarios and decisions regarding management of fibroids in the context of reproduction. Furthermore, the frequency with which clinicians encounter these issues will only increase as the trend toward delaying childbearing coincides with an increased incidence of fibroids in women later in their reproductive years.
Here we synthesize the complex literature on fibroids into evidence-based, pragmatic clinical recommendations for contemporary fibroid management.
The reproductive implications and therapeutic options for uterine fibroids are largely a function of their location. Classically, fibroid location has been divided into 3 categories: submucosal, intramural, and subserosal, though these terms are not universally consistent. Many fibroids lie in a gray area between these 3 distinct categories, which further complicates our ability to analyze existing data. Any discussion of management of fibroids and reproduction must start with a detailed description of the location of the fibroid in relation to the endometrial cavity. We feel that the FIGO classification scheme is the most useful organizational system published to date.2 This system is based on describing the proportion of the fibroid that is distorting the endometrial cavity because that is the single most important factor that affects the clinical implications and the type of treatment offered to the patient.
Submucosal fibroids are divided into 3 types. Type 0 are completely intracavitary (often described as “intracavitary myomata” rather than submucosal to distinguish them from other submucosal myomata that are partially or almost completely intramural). Type I fibroids have an intramural component, but >50% of the fibroid is located within the endometrial cavity. Type II fibroids also have an intramural component, but <50% is intracavitary. Intramural fibroids do not distort the endometrial cavity and have <50% of their mass protruding through the serosa. Fibroids extending >50% out of the serosal surface are considered subserosal.
Use of the FIGO classification scheme requires accurate delineation of the anatomic relationships as described, reinforcing the importance of optimal imaging techniques. Transvaginal ultrasound (TVUS) has been demonstrated to be a rapid and cost-effective means of evaluating uterine fibroids but may be limited by a variety of factors including the size and number of myomas as well as the acoustic shadowing they produce.
While initial studies reported high sensitivity and specificity for diagnosing endometrial cavity distortion in submucous myomas, more recent studies have demonstrated positive predictive values as low as 47%,3 thereby underscoring the need to utilize other, more effective imaging approaches including saline infusion sonography (SIS). SIS enhances the diagnostic accuracy of traditional ultrasound by creating a fluid interface through the instillation of saline into the uterine cavity. The degree to which the fibroid is contained within or distorts the cavity is usually more easily diagnosable; other pathology such as endometrial polyps may also be diagnosed more effectively.4
Although data are lacking, SIS may be further enhanced by 3D ultrasound. If the patient has multiple myomas or the uterus is quite large, ultrasound and/or SIS may not be effective in providing an accurate assessment of fibroid location. In these cases, magnetic resonance imaging (MRI) is the technique of choice for providing detailed mapping of the location and anatomic relationships of the fibroids.5