Endometrial scratching prior to IVF; does it help and for whom? A systematic review and meta-analysis.

STUDY QUESTION: What is the effect of endometrial scratching in patients with or without prior failed ART cycles on live birth (LBR) and clinical pregnancy rates (CPR)? SUMMARY ANSWER: It remains unclear if endometrial scratching improves the chance of pregnancy and, if so, for whom. WHAT IS KNOWN ALREADY: Endometrial scratching is hypothesized to improve embryo implantation in ART. Multiple studies have been published, but it remains unclear if endometrial scratching actually improves pregnancy rates and, if so, for which patients. STUDY DESIGN SIZE DURATION: For this review, a systematic search for published articles on endometrial scratching and ART was performed on 12 February 2018, in Pubmed, Embase and the Cochrane Library. PARTICIPANTS/MATERIALS SETTING METHODS: Randomized controlled trials (RCTs) that evaluated endometrial scratching in the cycle prior to the stimulation cycle and reported CPR or LBR were included. RCTs investigating the effect of scratching during the stimulation cycle, or prior to cryo-thaw cycles were excluded. Studies were assessed using the Cochrane Risk of Bias tool. The effect of scratching was assessed for three different patient groups: patients with no prior IVF/ICSI treatment (Group 0), patients with one failed full IVF/ICSI cycle, including cryo-thaw cycles (Group 1) and patients with two or more failed full IVF/ICSI cycles (Group 2). A meta-analysis was performed when statistical heterogeneity was low; otherwise, a descriptive analysis was performed. MAIN RESULTS AND THE ROLE OF CHANCE: Fourteen RCTs involving 2537 participants were included. Most RCTs contained a high or unclear risk of bias on one or more items. Substantial clinical and statistical heterogeneity was present; therefore meta-analysis for LBR and CPR could only be performed on Group 1. For this group, no differences between scratch and control were found for both LBR (risk ratio (RR) 1.01 [95%CI 0.68-1.51]) and CPR (RR 1.04 [95%CI 0.74-1.45]). For Groups 0 and 2, pooled analysis could not be performed, and for both groups the results of the individual RCTs were negative, neutral and positive. Miscarriage and multiple pregnancy rates were evaluated for the three groups (0, 1 and 2) together. Both outcomes were not significantly different between scratch and control (miscarriage rate RR 0.82 [95%CI 0.57-1.17] and multiple pregnancy rate RR 1.06 [95%CI 0.84-1.35]). Subgroup analysis, excluding trials with a risk of unintentional endometrial injury in the control group, was performed for Group 0 and 2 for LBR and CPR, and for the overall groups for miscarriage rate and multiple pregnancy rate. This reduced the heterogeneity and allowed for pooled analysis in these subgroups. Results of pooled analysis for the subgroups of Group 0 and 2 showed no significant difference for LBR, but CPR was significantly improved after endometrial scratching (Group 0 RR 1.28 [95%CI 1.02-1.62] and Group 2 RR 2.03 [95%CI 1.20-3.43]). Subgroup analysis of the overall groups showed no significant difference for miscarriage and multiple pregnancy rate. LIMITATIONS REASONS FOR CAUTION: The main limitations were that many RCTs had a high or unclear risk of bias on one or several items, clinical heterogeneity was still present despite categorizing into three populations, and that not all RCTs could be included in the analyses because separate data for our three groups could not be provided. WIDER IMPLICATIONS OF THE FINDINGS: It remains unclear if endometrial scratching improves the chance of pregnancy for women undergoing ART and, if so, for whom. This means endometrial scratching should not be offered in daily practice until results from large and well-designed RCTs and an individual patient data analysis become available. STUDY FUNDING/COMPETING INTERESTS: No specific funding was sought for the study. The Department of Reproductive Medicine and Gynaecology funds of the University Medical Center of Utrecht were used to support the authors throughout the study period and preparation of the manuscript. None of the authors has a conflict of interest to declare. REGISTRATION NUMBER: Not applicable.

Endometrial scratching in women with implantation failure after a first IVF/ICSI cycle; does it lead to a higher live birth rate? The SCRaTCH study: a randomized controlled trial (NTR 5342).

BACKGROUND: Success rates of assisted reproductive techniques (ART) are approximately 30%, with the most important limiting factor being embryo implantation. Mechanical endometrial injury, also called 'scratching', has been proposed to positively affect the chance of implantation after embryo transfer, but the currently available evidence is not yet conclusive. The primary aim of this study is to determine the effect of endometrial scratching prior to a second fresh in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycle on live birth rates in women with a failed first IVF/ICSI cycle. METHOD: Multicenter randomized controlled trial in Dutch academic and non-academic hospitals. A total of 900 women will be included of whom half will undergo an endometrial scratch in the luteal phase of the cycle prior to controlled ovarian hyperstimulation using an endometrial biopsy catheter. The primary endpoint is the live birth rate after the 2nd fresh IVF/ICSI cycle. Secondary endpoints are costs, cumulative live birth rate (after the full 2nd IVF/ICSI cycle and over 12 months of follow-up); clinical and ongoing pregnancy rate; multiple pregnancy rate; miscarriage rate and endometrial tissue parameters associated with implantation failure. DISCUSSION: Multiple studies have been performed to investigate the effect of endometrial scratching on live birth rates in women undergoing IVF/ICSI cycles. Due to heterogeneity in both the method and population being scratched, it remains unclear which group of women will benefit from the procedure. The SCRaTCH trial proposed here aims to investigate the effect of endometrial scratching prior to controlled ovarian hyperstimulation in a large group of women undergoing a second IVF/ICSI cycle. TRIAL REGISTRATION: NTR 5342 , registered July 31st, 2015. PROTOCOL VERSION: Version 4.10, January 4th, 2017.

The reliability of the histological diagnosis of endometritis in asymptomatic IVF cases: a multicenter observer study.

BACKGROUND: Chronic endometritis is associated with abnormal uterine bleeding, recurrent abortion and infertility. It is a subtle condition, and therefore is difficult to diagnose. The diagnosis is ultimately based on the presence of plasma cells in the endometrial stroma on histopathological examination. Literature on the reproducibility of the diagnosis of chronic endometritis is lacking. Therefore, the aim of the current study was to assess the interobserver agreement of two pathologists in diagnosing chronic endometritis in asymptomatic, infertile patients. METHODS: In the context of a randomized controlled trial, an endometrial biopsy was taken during a screening hysteroscopy prior to IVF. All endometrial samples were independently examined by two pathologist. The slides diagnosed with chronic endometritis were replenished with a random sample of the remaining slides up to a total of 100, then exchanged between the two pathologists and reassessed. RESULTS: Of the 678 patients who underwent hysteroscopy, 19 patients were diagnosed with at least possible chronic endometritis (2.8%). Perfect agreement between the pathologists, before and after inclusion of 13 slides with additional immunohistochemistry staining, was found in 88 and 86% of reviews, respectively. The interobserver agreement was substantial, with kappa-values of 0.55 and 0.66, respectively. CONCLUSIONS: The interobserver agreement in diagnosing chronic endometritis in asymptomatic infertile patients was found to be substantial. Although the diagnostic reliability is sufficient with the methods in the present study, the low prevalence and unknown clinical significance of endometritis warrants further study.

Observer agreement in the evaluation of the uterine cavity by hysteroscopy prior to in vitro fertilization.

BACKGROUND Hysteroscopy is known as the most accurate test for diagnosing intrauterine pathology. To optimize fertility treatment, it is increasingly common to perform hysteroscopy as a routine procedure prior to IVF. However, literature on the reproducibility of screening hysteroscopy is lacking. Therefore, the aim of the study was to assess the intra- and inter-observer agreement in the individual evaluation of the uterine cavity using video recordings of hysteroscopy procedures in asymptomatic patients prior to IVF. METHODS Screening hysteroscopies of 123 unselected, asymptomatic, infertile women with an indication for IVF/ICSI treatment were recorded on DVD. After editing, the hysteroscopy performer and three other experienced gynecologists independently assessed all recordings, focusing on the appearance of predefined intrauterine abnormalities (i.e. endometrial polyps, myomas, adhesions or septa). The intra- and inter-observer agreement was calculated and expressed as perfect agreement and κ coefficient or intraclass correlation coefficient. RESULTS In total, 123 hysteroscopy procedures were recorded. After editing and selection, based on the record quality, 107 remained for assessment and analysis. The intraobserver agreement on the appearance of any of the predefined intrauterine abnormalities was substantial (κ = 0.707), whereas the interobserver agreement was moderate (κ = 0.491). Perfect agreement occurred only in 77.6% of the cases. CONCLUSIONS Interobserver agreement among experienced gynecologists appeared to be rather disappointing. The latter may have implications for the diagnostic accuracy of screening hysteroscopy prior to IVF, as well as for its clinical significance in IVF programs.

Prevalence of unsuspected uterine cavity abnormalities diagnosed by office hysteroscopy prior to in vitro fertilization.

BACKGROUND: Whether implantation occurs after in vitro fertilization (IVF) depends on the embryo, uterine receptivity or a combination of both. The prevalence of minor intrauterine abnormalities identified at hysteroscopy in cases with a normal transvaginal sonography (TVS) has been recorded to be as high as 20-40%. Diagnosing and treating such pathology prior to initiating IVF/intra-cytoplasmic sperm injection (ICSI), has been widely advocated without high-quality evidence of a beneficial effect. The objective of the current study was to assess, by screening office hysteroscopy, the prevalence of unsuspected intrauterine abnormalities in an asymptomatic population of IVF patients, in whom TVS had not revealed any pathology. METHODS: The prevalence of unsuspected intrauterine abnormalities in patients allocated for a randomized controlled trial was prospectively assessed at two tertiary infertility care units: Academic Hospital at the Dutch-speaking Brussels Free University and University Medical Center Utrecht. A total of 678 unselected, asymptomatic, infertile women with a regular indication for a first IVF/ICSI treatment underwent office hysteroscopy. Only asymptomatic patients, aged < or = 42 years, with a normal TVS and no previous hysteroscopy were included. The presence of predefined intrauterine abnormalities was recorded and described in a standardized manner. RESULTS: Endometrial polyps were identified in 41 (6%) women and submucous myomas in 6 women (1%). Some women were also diagnosed with intrauterine adhesions (2%) or septa (2%). The overall prevalence of any predefined intrauterine abnormality in this IVF/ICSI population was 11%. CONCLUSIONS: The observed prevalence of unsuspected intrauterine abnormalities in asymptomatic patients indicated for their first IVF/ICSI treatment appeared to be clearly lower than previously reported (11 versus 20-45%). This may have implications for the significance of these abnormalities regarding prospects in IVF/ICSI treatment cycles.