Uterine Factors Pathologies within the uterine cavity are the cause of infertility in as many as 15% of couples seeking treatment and are diagnosed in greater than 50% of infertile patients (231). Therefore, the evaluation of the couple with infertility should consistently include an assessment of the endometrial cavity. Uterine cavity abnormalities include endometrial polyps, endometrial hyperplasia, submucous myomas, intrauterine synechiae, and congenital uterine anomalies (232).
Hysteroscopy Hysteroscopy is considered the gold standard for uterine cavity evaluation because it allows for direct visualization. The procedure involves insertion of an endoscope through the cervical canal into the uterine cavity and instillation of distension media to allow for visualization (231–233). Diagnostic hysteroscopy may be performed in the office using a small-diameter hysteroscope and saline distension, often without need for anesthesia (232). To optimize visualization of the endometrial cavity and avoid performing the procedure during early pregnancy, hysteroscopy is typically scheduled during the early-to midfollicular phase of the cycle. Disadvantages to the procedure include poor visualization when uterine bleeding is present and the inability to evaluate structures outside the uterine cavity, including those in the myometrium and adnexa. Office hysteroscopy is reported to have a 72% sensitivity for cavity abnormalities when compared to operative hysteroscopy using general anesthesia (231).
Hysterosalpingogram Insofar as it allows assessment of both tubal and intrauterine pathology, HSG is a reasonable initial imaging technique to use in the basic infertility evaluation. Hysterosalpingogram shows the general configuration of the uterine cavity and indicates endometrial lesions as filling defects or irregularities of the intrauterine wall. Excessive contrast may lead to false-negative findings, which may account for the 50% sensitivity of HSG compared to hysteroscopy for endometrial polyps. Inability to discriminate air bubbles, mucous, and debris from true intracavitary pathology may account for HSG’s high false-positive rate when compared with hysteroscopy (232,233). Other drawbacks include patient discomfort, use of iodinated contrast, and radiation exposure (232).
Transvaginal Ultrasound Compared to hysteroscopy, transvaginal ultrasound has a 75% positive predictive value and 96.5% negative predictive value for intracavitary polyps but a 0% positive predictive value for intrauterine adhesions. Similar to HSG, it has a sensitivity of 44% for uterine malformations (233). However, this may be improved significantly with the use of three-dimensional technology.
Sonohysterography Saline infusion sonography (SIS), synonymous with sonohysterography, involves the transcervical instillation of saline, often via a balloon catheter, during transvaginal ultrasound to distend the uterine cavity and delineate the endometrium. As with office hysteroscopy and HSG, SIS is performed during the follicular phase of the cycle and anesthesia typically is not required. Endometrial polyps appear as hyperechogenic pedunculated lesions, submucous fibroids have mixed echogenicity, and adhesions contain densely echogenic and cystic areas (234). Compared to hysteroscopy, SIS has 100% sensitivity, specificity, and