Chronic endometritis in women with recurrent pregnancy loss and recurrent implantation failure: prevalence and role of ofce hysteroscopy and immunohistochemistry in diagnosis Pierre-Emmanuel Bouet, M.D., M.Sc., a,b Hady El Hachem, M.D., M.Sc., a,b Elise Monceau, M.D., a,b Gilles Gariepy, M.D., c Isaac-Jacques Kadoch, M.D., a,b and Camille Sylvestre, M.D. a,b a Department of Reproductive Medicine, Ovo Clinic; and b Department of Obstetrics and Gynecology and c Department of Pathology, University of Montreal, Montreal, Quebec, Canada Objective: To determine the prevalence of chronic endometritis (CE) in patients with recurrent implantation failure (RIF) after IVF and unexplained recurrent pregnancy loss (RPL). Design: Prospective observational study between November 2012 and March 2015. Setting: University-afliated private IVF clinic. Patient(s): Women with RIF after IVF (group 1) and unexplained RPL (group 2). Intervention(s): Ofce hysteroscopy followed by an endometrial biopsy was performed as part of the workup for RIF and RPL. The diagnosis of CE was histologically conrmed using immunohistochemistry stains for syndecan-1 (CD138). Main Outcome Measure(s): The prevalence of CE in each group and the sensitivity/specicity of ofce hysteroscopy in the diagnosis of CE. Result(s): Ninety-nine patients were included (46 in group 1 and 53 in group 2). The mean age was 36.3 4.9 years in group 1 and 34.5 4.9 years in group 2. Five biopsies were uninterpretable (three in group 1 and two in group 2) because of insufcient specimen. The prevalence of CE was 14% (6/43) in group 1 and 27% (14/51) in group 2. The sensitivity and specicity of ofce hysteroscopy in the diagnosis of CE were 40% (8/20) and 80% (59/74), respectively. Conclusion(s): We found a high prevalence of immunohistochemically conrmed CE in women with RIF and RPL. Ofce hysteroscopy is a useful diagnostic tool but should be complemented by an endometrial biopsy for the diagnosis of CE. Clinical Trial Registration No.: NCT01762098. (Fertil Steril Ò 2016;105:10610. Ó2016 by American Society for Reproductive Medicine.) Key Words: Chronic endometritis, recurrent pregnancy loss, implantation failure, plasma cells, ofce hysteroscopy Discuss: You can discuss this article with its authors and with other ASRM members at http:// fertstertforum.com/bouetpe-chronic-endometritis-rpl-rif/ Use your smartphone to scan this QR code and connect to the discussion forum for this article now.* * Download a free QR code scanner by searching for QR scannerin your smartphones app store or app marketplace. T he endometrial factor in recur- rent implantation failure (RIF) after IVF and recurrent preg- nancy loss (RPL) is under constant scrutiny. One of the etiologies is chronic endometritis (CE), which is dened as a chronic inammation of the endometrial lining (1). Patients are usually asymptomatic but can present with chronic pelvic pain, dyspareunia, abnormal uterine bleeding, or persis- tent vaginal discharge (1). Ofce hys- teroscopy can help diagnose CE with direct visualization of mucosal edema, focal or diffuse endometrial hyperemia, and micropolyps (<1 mm) (2). Howev- er, the gold standard for the diagnosis of CE is histological identication of Received July 27, 2015; revised September 2, 2015; accepted September 17, 2015; published online October 9, 2015. P.-E.B. has nothing to disclose. H.E.H. has nothing to disclose. E.M. has nothing to disclose. G.G. has nothing to disclose. I.-J.K. has nothing to disclose. C.S. has nothing to disclose. Reprint requests: Dr. Pierre-Emmanuel Bouet, M.D., M.Sc., Department of Reproductive Medicine, Ovo Clinic, 8000 Boulevard Decarie, Montreal, Quebec H4P 2S4, Canada (E-mail: pebouet@ hotmail.com). Fertility and Sterility® Vol. 105, No. 1, January 2016 0015-0282/$36.00 Copyright ©2016 American Society for Reproductive Medicine, Published by Elsevier Inc. http://dx.doi.org/10.1016/j.fertnstert.2015.09.025 106 VOL. 105 NO. 1 / JANUARY 2016 ORIGINAL ARTICLES: EARLY PREGNANCY