BJOG: An International Journal of Obstetrics & Gynaecology | 2019
Management of unilateral tubal block at hysterosalpingogram
Abstract
Hysterosalpingogram (HSG) is a commonly used test to evaluate the uterine cavity and assess patency of the fallopian tubes among women who present with infertility. As a diagnostic test, HSG has relatively high negative predictive value (94%, fallopian tubes patent with normal HSG) but relatively low positive predictive value (38%, fallopian tubes blocked with abnormal HSG) (Evers et al. Semin Reprod Med 2003;21:9–15). The predictive value does vary depending whether proximal or distal obstruction is identified. As many as 60% of patients with bilateral proximal obstruction at HSG demonstrate bilateral fill and spill at the time of second HSG (Dessole et al. Fertil Steril 2000;73:1037–9). In these cases, the initially identified obstruction is often attributed to transient tubal spasm or other reversible blockage such as debris. No information is learned about the fallopian tube that demonstrates proximal blockage as it is entirely nonvisualized. This leaves multiple possibilities: the tube is normal and patent, and the test is false positive; the tube is proximally obstructed and the test is true positive; or the tube is distally obstructed and may even represent an undiagnosed hydrosalpinx. Distal blockage, by contrast, is often the result of a prior inflammatory process and can indicate the presence of hydrosalpinx, which has been associated with lower rates of conception during treatment with in vitro fertilization (IVF), whether bilateral or unilateral, and outcomes can be improved by performing salpingectomy prior to treatment. (Kassabji et al. Eur J Obstet Gynecol Reprod Biol 1994;56:129–32; Murray et al. Fertil Steril 1998;69(1):41–5). Extrapolating this data to intrauterine insemination (IUI) cycles would suggest that women with unilateral distal tubal obstruction have a worse prognosis. Identifying a single patent tube at the time of HSG is a relatively common occurrence for providers who order or perform this test regularly. For women with bilateral tubal obstruction, the choices are surgery, IVF, or both, depending on the clinical situation. For women with one confirmed patent tube, intrauterine insemination is also a possible method of treatment and may be the first choice of many patients who live in regions with low rates of insurance coverage for IVF. Prospective randomized studies to assist in counselling women with unilateral tubal obstruction undergoing IUI are lacking. This systematic review and metaanalysis (BJOG 2019;126:227–35) strives to combine current knowledge about unilateral tubal obstruction on HSG in patients undergoing IUI without prior surgical treatment for tubal block. The author’s findings are reassuring that patients with proximal obstruction have good prognoses, and our suspicion that the presence of hydrosalpinx is likely detrimental seems to be supported by the lower pregnancy rate demonstrated in the group with distal obstruction. When surveyed, about 1 in 4 fertility providers reported routinely removing or ligating unilateral hydrosalpinx prior to IUI (Omurtag et al. Fertil Steril 2012;97:1095–100.e1-2). The open question of whether salpingectomy for hydrosalpinx is warranted prior to IUI does remain, however, and there are no randomized trials to guide management. The findings of this study, which compiles available retrospective and cross-section evidence, provide useful additional information for use in patient counselling.