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

Abstract

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 scratchin...

Effect of endometrial injury during menstruation on clinical outcomes in frozen–thawed embryo transfer cycles: A randomized control trial

“… The statement above has also been proved by several recent meta‐analysis studies . However, in 2019, another two systematic reviews suggested that current evidence did not fully support performing EI with the purpose of improving success of a first ET attempt . Therefore, the clinical application of EI is still in controversial, especially for the frozen–thawed ET process due to the lack of evidence.…”

“…However, there is no consensus in the field up to date and the benefit of EI prior to embryo transfer is controversial. Specifically, some studies demonstrated that performing EI in luteal phase prior to in vitro fertilization (IVF)/ICSI improved implantation and clinical pregnancy rates, in the meanwhile, there are some studies denied such benefit of EI . It is important to point out that most previous studies focused on fresh embryo transfer.…”

“…Specifically, some studies demonstrated that performing EI in luteal phase prior to in vitro fertilization (IVF)/ICSI improved implantation and clinical pregnancy rates, [2][3][4][5][6][7][8][9][10] in the meanwhile, there are some studies denied such benefit of EI. [11][12][13][14][15][16] It is important to point out that most previous studies focused on fresh embryo transfer.…”

Endometrial scratch for infertile polycystic ovary syndrome (PCOS) women undergoing laparoscopic ovarian drilling: a randomized controlled trial

“…Many studies had shown a potential benefit of the procedure in improving fertility performance in women with previous IVF failure undergoing a fresh cycle [13,14]. However, the most recent systematic review has reported no effect of the procedure on women undergoing IVF treatment with a previous one failed IVF cycle [23]. However, there is still uncertainty about the value of the procedure in women undergoing it for the first time [23][24][25].…”

“…However, the most recent systematic review has reported no effect of the procedure on women undergoing IVF treatment with a previous one failed IVF cycle [23]. However, there is still uncertainty about the value of the procedure in women undergoing it for the first time [23][24][25].…”