Saline Sonography vs Hysteroscopy for Evaluation of the Uterine Cavity

Introduction: Saline infusion sonography (SIS) and hysteroscopy are commonly used methods for the evaluation of the uterine cavity prior to fertility treatments. One common finding that may inhibit or prolong fertility treatment is uterine polyps. The prevalence of polyps in patients with abnormal uterine bleeding has been reported to range from 13-50%. The incidence of disease in primary infertility is 3.8%–38.5%, and 1.8%–17% in secondary infertility. It has a combined infertility incidence of 1.9%–24%. Transvaginal ultrasound (TVUS) is an easy and cost effective method for initial assessment of the uterine cavity, however cannot distinguish intrauterine pathology with certainty. Hysteroscopy is the gold standard for diagnosis of intrauterine pathology, however it is invasive, expensive, and requires anesthesia. SIS is a cheaper and less invasive alternative to hysteroscopy that can identify intrauterine pathology with reasonable accuracy. Methods: The objective of this study was to compare the sensitivity and specificity of saline sonography to hysteroscopy in identifying uterine polyps in patients with infertility. Patients were identified by searching the patient database at Florida Fertility Institute by CPT 58558, which codes for a surgical hysteroscopy with biopsy and/or polypectomy, from September 1, 2022 to September 23, 2024. One hundred and 29 patient charts were identified. Paper charts were manually evaluated by a single investigator and de-identified results were collected. After accounting for exclusion criteria, the final sample size was 127 patients. Exclusion criteria included missing pathology reports, incomplete records, Mullerian anomalies, cancer, and complications from surgery. Some patients underwent hysteroscopy multiple times and encounters were documented as separate data points. Statistical analyses were then performed to obtain sensitivity, specificity, positive predictive value, and negative predictive values for various imaging studies. Results: This study demonstrated that within this patient population, SIS had a similar sensitivity to hysteroscopy, 95.31% and 95.51% respectively. Therefore, 95% of patients with polyps would have positive testing for polyps on SIS. SIS can be performed in the office, is inexpensive, and has less complications compared with hysteroscopy. TVUS demonstrated a sensitivity of 47.62% and specificity of 76.47%. TVUS is an easy and cost effective method for initial assessment of the uterine cavity, however cannot distinguish intrauterine pathology with certainty, and is better for ruling out polyps.​ Endometrial biopsy (EMB) and hysterosalpingogram (HSG) had better sensitivity than TVUS for evaluation of polyps, 70% and 84.62% respectively. Limitations that exist within this study included the chance of error as information was collected manually from paper charts, small sample sizes within each imaging modality group, and a potential for bias due to patients who had multiple imaging studies done with prior positive results. It is also provider dependent on which study is completed and the order of completion, therefore sample sizes are varying. Conclusion: In conclusion, hysteroscopy is an excellent sensitive method for evaluation of the uterine cavity, however saline infusion sonography may be just as sensitive and have more advantages. Providers should consider in-office SIS prior to hysteroscopy for evaluation of the uterine cavity when endometrial polyp is suspected.