Study	Reason for exclusion
Abiri 2014	Not addressing the research questions described in the protocol. RCT in women with no suspected major uterine cavity abnormalities undergoing a first IVF treatment cycle.
Abu Rafea 2013	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing intrauterine balloon stenting vs no stenting following hysteroscopic treatment for septate uterus.
Acunzo 2003	Not addressing the research questions described in the protocol. Parallel‐group randomised trial studying the efficacy of hyaluronic acid gel in preventing the development of intrauterine adhesions following hysteroscopic adhesiolysis. Mixed population of women with intrauterine adhesions, presenting with subfertility or other gynaecological complaints. Primary outcome: adhesion scores.
Aghahosseini 2012	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing hysteroscopy prior to a subsequent IVF attempt vs immediate IVF without prior hysteroscopy conducted in women with ≥ 2 failed IVF cycles with unsuspected or no uterine cavity abnormalities. Main outcomes: biochemical pregnancy, clinical pregnancy and delivery rates.
Aghajanova 2018	Not addressing the research questions described in the protocol. Randomised controlled open pilot clinical trial studying the efficacy of the intrauterine infusion of autologous platelet rich plasma vs saline infusion after operative hysteroscopy for the management of moderate‐to‐severe Asherman's syndrome.
Aleyassin 2017	Not addressing the research questions described in the protocol. RCT studying the effectiveness of routine hysteroscopy compared to no prior hysteroscopy in women with normal transvaginal ultrasound and HSG before the first ICSI treatment cycle.
Amer 2010	Not addressing the research questions described in the protocol. Parallel‐group randomised trial in subfertile women comparing the application of amnion graft, either fresh or dried to an intrauterine balloon vs the application of an intrauterine balloon without amnion graft as an adjunctive procedure after the hysteroscopic lysis of severe intrauterine adhesions, diagnosed at clinic hysteroscopy in women with infertility with or without menstrual disorders as the primary symptom. Outcomes: improvement in adhesion grade, improvement in menstruation, increased uterine length at sounding, complications and reproductive outcome.
Basma 2013	Not addressing the research questions described in the protocol. Women with detectable uterine pathology by ultrasound were excluded from participating in the trial aiming to study the effectiveness of hysteroscopy before a first trial ICSI.
Cao 2018	Not addressing the research questions described in the protocol. Systematic review including clinical trials of hysteroscopy with or without endometrial biopsy in women with recurrent implantation failure and no suspected intrauterine lesions.
Chen 2017	Not addressing the research questions described in the protocol. RCT investigating the effects of mindfulness‐based stress reduction on anxiety, depression and quality of life in women with intrauterine adhesions.
Clark 2015	Not addressing the research questions described in the protocol. The target population included women with abnormal uterine bleeding and hysteroscopically diagnosed uterine polyps.
Colacurci 2007	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing 2 different surgical techniques for metroplasty: operative hysteroscopy using the resectoscope with a unipolar knife vs the Versapoint device. Mixed population of women with septate uterus and a history of recurrent miscarriage or primary subfertility. Outcomes: operative parameters, complications, need for a second intervention and reproductive outcome parameters.
Darwish 2009	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing extended sectioning by resectoscopy vs sequential cold knife excision for treating a complete utero‐cervicovaginal septum in a mixed population of women with infertility or pregnancy loss. Main outcomes: operating time, perioperative bleeding, complications, reproductive outcome, and participant and husband satisfaction.
De Angelis 2010	Study on the effectiveness of hysteroscopic metroplasty for small septate uterus in women with repeated IVF implantation failure. Although denoted by the authors as the first prospective randomised controlled study on this subject, the trial did not use a valid random sequence generation. Quote: "These patients, once informed about the situation, were randomly allocated, depending on their personal decision ..."
De Iaco 2003	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing the application of hyaluronan derivative gel (Hyalobarrier gel) after hysteroscopic surgery vs surgical treatment alone in women aged 18–65 years, with gynaecological conditions other than subfertility. Primary outcome: adhesion score at second‐look hysteroscopy.
Demirol 2004	Not addressing the research questions described in the protocol. Parallel‐group randomised comparison between clinic hysteroscopy prior to a subsequent IVF attempt or immediate IVF without prior clinic hysteroscopy conducted in women with ≥ 2 failed IVF cycles with unsuspected or no uterine cavity abnormalities. Outcomes: number of oocytes retrieved, fertilisation rate, number of embryos transferred, first trimester miscarriage and clinical pregnancy rates.
Di Florio 2013	Not addressing the research questions described in the protocol. RCT comparing the new 16 Fr mini‐resectoscope with the traditional 22 Fr resectoscope and Bettocchi 15 Fr hysteroscope for the treatment of uterine cavitary lesions.
Di Spiezio Sardo 2011	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing the use of Intercoat absorbable adhesion barrier gel vs no adhesion barrier after hysteroscopic synechiolysis in a mixed population of women with infertility or other gynaecological conditions. Primary outcomes: incidence of de novo intrauterine adhesions, adhesion scores and patency of the internal uterine ostium.
El‐Khayat 2015	Not addressing the research questions described in the protocol. RCT evaluating the role of endometrial injury in the cycle preceding ovarian stimulation for IUI cycle on the clinical pregnancy rate.
El‐Nashar 2011	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing diagnostic hysteroscopy with directed biopsy or hysteroscopic treatment of unsuspected uterine cavity abnormalities (or both) vs no hysteroscopy in women with primary infertility treated with ICSI. Primary outcome: clinical pregnancy.
El‐Toukhy 2009	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing hysteroscopy vs no hysteroscopy in women with recurrent implantation failure with IVF. Status: completed.
Elsetohy 2015	Not addressing the research questions described in the protocol. Parallel‐group randomised trial aimed at assessing the role of using clinic hysteroscopy as a routine investigation in improving ICSI pregnancy rates in 2 groups of infertile women with no abnormality detected on transvaginal ultrasonographic examination.
Fatemi 2007	Not addressing the PICO research question of this Cochrane Review.
Fuchs 2014	Not addressing the PICO research question of this Cochrane review. RCT evaluating the safety and effectiveness of Oxiplex/AP gel (Intercoat) in reducing intrauterine adhesion formation after hysteroscopic treatment because of retained products of conception.
Gan 2017	Not addressing the PICO research question of this Cochrane Review. RCT studying the efficacy of freeze‐dried amnion graft for prevention of intrauterine adhesion reformation after hysteroscopic adhesiolysis.
Gao 2013	Observational non‐randomised study on the effectiveness of hysteroscopy in women with repeated implantation failure.
Guida 2004	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing hysteroscopic surgery for the removal of polyps, fibroids or septa followed by the application of auto‐cross linked hyaluronic acid gel vs hysteroscopic surgery without the adhesion barrier in a mixed population of women with subfertility and other gynaecological symptoms associated with endometrial polyps, submucous fibroids or septa. Main outcomes: rates of adhesion formation and adhesion scores.
Guo 2017	Not addressing the research questions described in the protocol. Prospective, randomised, controlled trial to evaluate the efficacy of different doses of oestrogen treatment (2  mg and 6  mg daily) after hysteroscopic adhesiolysis in women with moderate‐to‐severe adhesion according to the American Fertility Society classification of intrauterine adhesions.
Hamerlynck 2015	Not addressing the research questions described in the protocol. Multicentre, open‐label, randomised, controlled trial comparing hysteroscopic morcellation with bipolar resectoscopy for removal of endometrial polyps, in terms of procedure time, peri‐ and postoperative adverse events, tissue availability and short‐term effectiveness.
Hanstede 2016	Not addressing the research questions described in the protocol. Single‐blind RCT assessing whether exogenous hormone administration starting immediately after a successful hysteroscopic adhesiolysis, in women with Asherman's syndrome may reduce the incidence of spontaneous recurrence of adhesions more than the endogenic production of hormones.
Hare 2013	Not addressing the research questions described in the protocol. Randomised controlled study examining the effect of scratching in a normal visually and histologically endometrium. Women with uterine pathology were excluded before or during clinic hysteroscopy.
Javidan 2017	Not addressing the research questions described in the protocol. Single‐blind RCT to assess the outcomes of surgery in a group of women who were randomly submitted to preoperative gonadotropin‐releasing hormone agonists in comparison with women who received no medication.
Kamel 2014	Not addressing the research questions described in the protocol. Randomised controlled study to compare mechanical (cold scissor) vs electrosurgical metroplasty (bipolar twizzle) in terms of feasibility and pain scoring during ambulatory‐based hysteroscopic metroplasty for short, narrow‐based uterine septa.
Lara‐Dominguez 2016	Not addressing the research questions described in the protocol. RCT comparing the resection of endometrial polyps with 2 different devices: the Versapoint bipolar electrode and the diode laser.
Lieng 2010a	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing transcervical resection by hysteroscopy of endometrial polyps suspected on TVUS and SIS vs observation for 6 months. The study population included premenopausal women with bleeding problems associated with endometrial polyps. The aim of the trial was to study the clinical effectiveness of transcervical resection of endometrial polyps for the outcome periodic blood loss. Women wishing to become pregnant were excluded from the trial. Primary outcome: periodic blood loss measured by the Pictorial Blood Assessment Chart.
Lin 2014	Not addressing the research questions described in the protocol. Randomised trial comparing the efficacy of intrauterine balloon and intrauterine contraceptive device in the prevention of adhesion reformation following hysteroscopic adhesiolysis.
Liu 2016	Not addressing the research questions described in the protocol. RCT randomly comparing oestradiol valerate (Progynova) 3 mg or 9  mg per diet before surgery or no hormonal treatment before transcervical resection of adhesions.
Mohammed 2014	Comparative non‐randomised study on the value of hysteroscopy prior to IVF/ICSI.
Moramezi 2012	Not addressing the research questions described in the protocol. RCT studying the effectiveness of hysteroscopy before IUI on reproductive outcome in infertile women with no suspected intrauterine lesions during baseline fertility assessment.
Muzii 2007	Not addressing the research questions described in the protocol. Parallel‐group randomised trial in women aged 18–75 years comparing operative hysteroscopy using the monopolar resectoscope vs hysteroscopic bipolar electrode excision for the treatment of endometrial polyps. Outcomes: operating times, difficulty of the operation, surgeon satisfaction with the procedure, complications, postoperative pain and participant satisfaction.
Muzii 2017	Not addressing the research questions described in the protocol. Multicentric randomised trial in 180 women affected by endometrial hyperplasia, myomas or endometrial polyps undergoing operative hysteroscopy comparing cefazolin 2 g intravenously 30 minutes prior to the procedure vs no antibiotic treatment.
Nappi 2013	Not addressing the research questions described in the protocol. Double‐blind, randomised, placebo‐controlled study to assess the incidence of infectious complications and the protective effect of antibiotic administration during operative hysteroscopic procedures in a clinic setting. 1046 consecutively enrolled women with intrauterine lesions were randomly allocated to the intervention group (523 participants administered cefazolin 1 g intramuscularly) and the control group (523 participants administered with 10 mL of isotonic sodium chloride solution), and treated in clinic setting by operative hysteroscopy for endometrial polypectomy, uterine septa, submucosal myomas and intrauterine adhesions.
Pabuccu 2008	Quasi‐randomised trial comparing early second‐look clinic hysteroscopic adhesiolysis after hysteroscopic adhesiolysis and IUD insertion vs no early second‐look operative hysteroscopy in subfertile women with intrauterine adhesions. The method of sequence generation was based on alternation: women were allocated to the intervention or control groups based on their study entry. Main outcomes: pregnancy and live birth rate.
Parsanezhad 2006	Not addressing the research questions described in the protocol. Parallel‐group randomised trial in a mixed study population of women with a history of pregnancy wastage or infertility and an associated complete uterine septum comparing metroplasty with complete section of the cervical septum vs metroplasty with preservation of the cervical septum. Outcomes: operating time, distending media deficit, total distending media used, intraoperative bleeding, complications and reproductive outcome.
Paz 2014	Not addressing the research questions described in the protocol. Randomised, double‐blind, controlled trial to evaluate the efficacy and safety of Intercoat (Oxiplex/AP Gel) in preventing intrauterine adhesions after operative hysteroscopy.
Rama Raju 2006	Not addressing the research questions described in the protocol. Parallel‐group randomised trial conducted in women with ≥ 2 failed IVF cycles with unsuspected or no uterine cavity abnormalities comparing clinic hysteroscopy prior to a subsequent IVF attempt or immediate IVF without prior hysteroscopy. Outcomes: number of oocytes retrieved, fertilisation rate, number of embryos transferred and clinical pregnancy rates.
Revel 2011	Not addressing the research questions described in the protocol. Parallel‐group RCT assessing the safety of hyaluronic acid gel to prevent intrauterine adhesions in hysteroscopic surgery
Roy 2014	Not addressing the research questions described in the protocol. RCT to evaluate the efficacy of oestrogen in preventing intrauterine adhesions following hysteroscopic septal resection and to investigate its effect on reproductive outcome.
Roy 2015	Not addressing the research questions described in the protocol. RCT to compare the operation and reproductive outcome of hysteroscopic septal resection using unipolar resectoscope vs bipolar resectoscope.
Roy 2017	Not addressing the research questions described in the protocol. Randomised, prospective, parallel, comparative, single‐blinded study comparing the operative and reproductive outcome of hysteroscopic myomectomy using unipolar resectoscope vs bipolar resectoscope in women with infertility and menorrhagia.
Rubino 2015	Not addressing the research questions described in the protocol. Randomised, prospective, comparative setting clinical trial to examine efficacy of hysteroscopic removal of polyps and myomas on health‐related quality of life and symptom severity at 1‐year postprocedure in a clinic vs ambulatory surgical centre.
Shawki 2012	Not addressing the research questions described in the protocol. Parallel‐group randomised trial conducted to determine the incidence of unsuspected uterine cavity abnormalities detected by clinic hysteroscopy in women before ICSI treatment compared to ICSI without prior hysteroscopy. Main outcomes: incidence of unsuspected uterine abnormalities, and implantation and clinical pregnancy rates.
Shokeir 2010	Published report describing a parallel‐group randomised trial comparing hysteroscopic myomectomy vs diagnostic hysteroscopy and biopsy in women with otherwise unexplained primary infertility and submucous fibroids. Primary outcome: clinical pregnancy rates. Quote from Fertility and Sterility searched on 16 January 2012: "This article has been retracted at the request of the editor as it duplicates parts of a paper that had already appeared in Hum. Reprod., 20 (2005) 1632–1635, DOI:10.1093/humrep/deh822."
Smit 2015	Not addressing the research questions described in the protocol. RCT assessing the interobserver agreement among gynaecologists who were randomised into 2 groups: 1 group received diagnostic criteria for a septate uterus before assessment of videos, whereas the other group assessed the recordings without instruction.
Smit 2016	Not addressing the research questions described in the protocol. Pragmatic, multicentre, RCT in women with a normal TVUS of the uterine cavity and no previous hysteroscopy who were scheduled for their first IVF treatment randomly comparing treatment with hysteroscopy of detected intracavitary abnormalities before starting IVF vs immediate start of the IVF treatment.
Smith 2014	Not addressing the research questions described in the protocol. Multicentre, single‐blind, randomised, controlled trial to evaluate whether hysteroscopic morcellation or bipolar electrosurgical resection was more favourable for removing endometrial polyps in a clinic setting in terms of feasibility, speed, pain and acceptability.
Sohrabvand 2012	Not addressing the research questions described in the protocol. Parallel‐group RCT to assess the effectiveness of diagnostic hysteroscopy in women prior to IVF/IICSI. The study population included women with a normal hysterosonography and normal vaginal ultrasound during the past 12 months.
Tonguc 2010	Not addressing the research questions described in the protocol. Parallel‐group randomised study comparing hysteroscopic lysis of intrauterine adhesions with or without adjunctive therapy (cyclical hormone replacement therapy alone or intrauterine device alone or both cotreatments combined) after hysteroscopic metroplasty in a mixed population of women with subfertility or recurrent miscarriage (or both). Main outcomes: incidence of de novo adhesion formation and ongoing pregnancy rate.
Trninić‐Pjević 2011	Clinical controlled trial on the effectiveness of hysteroscopy prior to IVF; no random sequence generation.
van Dongen 2008	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing the hysteroscopic removal of polyps or fibroids by conventional hysteroscopy using a resectoscope vs hysteroscopic morcellation in a mixed population of women with infertility or other gynaecological conditions. Outcomes: mean number of insertions into the uterine cavity and mean operating time.
Vercellini 1993	Not addressing the research questions described in the protocol. Parallel‐group randomised comparing metroplasty using the resectoscope vs microscissors for treating uterine septum in women with repeated miscarriage. Outcomes: mean operating time, mean amount of distension medium used and complications.
Weiss 2005	Not addressing the research questions described in the protocol. Parallel‐group RCT to determine whether performing curettage the month prior to embryo transfer increases the chance of embryo implantation.
Xiao 2015	Not addressing the research questions described in the protocol. Prospective, randomised, double‐blind, controlled clinical trial assessing the efficacy and safety of auto‐crosslinked hyaluronic acid gel for preventing intrauterine adhesions after hysteroscopic adhesiolysis.
Youssef 2013	Not addressing the research questions described in the protocol. Parallel‐group randomised trial comparing 2 different surgical techniques for metroplasty: resectoscopy with monopolar knife vs small‐diameter hysteroscopy fitted with a 5 Fr reusable bipolar electrode. Outcomes: pregnancy, miscarriage and live birth rates.

HSG: hysterosalpingography; ICSI: intracytoplasmic sperm injection; IUD: intrauterine device; IUI: intrauterine insemination; IVF: in vitro fertilisation; PICO: Participants, Interventions, Comparisons and Outcomes; RCT: randomised controlled trial; SIS: saline infusion sonography; TVUS: transvaginal ultrasound.