Evaluation of the effect of endometrial scratch by hysteroscopic scissors on frozen embryo transfer outcomes: A historical cohort study
Background: Endometrial scratch (ES) has been suggested to improve assisted reproductive techniques success rates by investigating implantation failure.
Objective: In this study, we evaluated the effect of ES on the outcomes of frozen embryo transfer (FET) in women with at least 2 failed embryo transfer cycles.
Materials and Methods: In this historical cohort study, medical data of 236 infertile women who underwent in-vitro fertilization-FET at Ebne-sina Infertility Center, Tehran, Iran, from January 2015-December 2021 was extracted from their medical records. Based on having ES before FET, they were assigned to either the scratch (n = 118) or the no-scratch group (n = 118). We compared these groups regarding pregnancy rates and outcomes.
Results: The demographic characteristics were similar in both groups regarding weight, body mass index, the number of previous embryo transfers, and the duration of infertility. However, the scratch group had a slightly higher mean age (32.31 vs. 29.96 yr, p < 0.001). No statistically significant difference was observed between groups regarding pregnancy rate (p = 0.89). No significant association was observed between scratch, infertility duration, the number of previous FET attempts, and the likelihood of pregnancy in a logistic regression model. No major complications were observed.
Conclusion: Hysteroscopic endometrial scratching with scissors probably has no effect on FET outcomes, including pregnancy or live birth rates.
Key words: Hysteroscopy, Infertility, Pregnancy rate, Live birth.
 Centers for Disease Control and, Prevention. Assisted reproductive technology national summary report 2018. US: US Dept of Health and Human Services; 2021.
 De Geyter Ch, Calhaz-Jorge C, Kupka MS, Wyns C, Mocanu E, Motrenko T, et al. ART in Europe, 2014: Results generated from European registries by ESHRE: The European IVF-monitoring consortium (EIM) for the European Society of Human Reproduction and Embryology (ESHRE). Hum Reprod 2018; 33: 1586–1601.
 Kang YF, Wang ZhH, Yang Y, Liang HZh, Duan X, Gao Qh, et al. Impact of endometrial scratching on reproductive outcome in patients: A systematic review and metaanalysis. Medicine (Baltimore) 2022; 101: e30150.
 van Hoogenhuijze NE, Mol F, Laven JSE, Groenewoud ER, Traas MAF, Janssen CAH, et al. Endometrial scratching in women with one failed IVF/ICSI cycle-outcomes of a randomised controlled trial (SCRaTCH). Hum Reprod 2021; 36: 87–98.
 Duffy JMN, Adamson GD, Benson E, Bhattacharya S, Bofill M, Brian K, et al. Top 10 priorities for future infertility research: An international consensus development study. Fertil Steril 2021; 115: 180–190.
 Barash A, Dekel N, Fieldust S, Segal I, Schechtman E, Granot I. Local injury to the endometrium doubles the incidence of successful pregnancies in patients undergoing in vitro fertilization. Fertil Steril 2003; 79: 1317– 1322.
 Valdes CT, Schutt A, Simon C. Implantation failure of endometrial origin: It is not pathology, but our failure to synchronize the developing embryo with a receptive endometrium. Fertil Steril 2017; 108: 15–18.
 Sehring J, Beltsos A, Jeelani R. Human implantation: The complex interplay between endometrial receptivity, inflammation, and the microbiome. Placenta 2022; 117: 179–186.
 Shekibi M, Heng S, Nie G. MicroRNAs in the regulation of endometrial receptivity for embryo implantation. Int J Mol Sci 2022; 23: 6210.
 Potdar N, Gelbaya T, Nardo LG. Endometrial injury to overcome recurrent embryo implantation failure: A systematic review and meta-analysis. Reprod Biomed Online 2012; 25: 561–571.
 Baradwan S, Saeed Alshahrani M, AlSghan R, Alkhamis WH, Alsharif SA, Alanazi GA, et al. The effect of endometrial scratch on pregnancy rate in women with previous intrauterine insemination failure: A systematic review and meta-analysis of randomized controlled trials. Reprod Sci 2022; 30: 1399–1407.
 Lensen SF, Armstrong S, Gibreel A, Nastri CO, Raine- Fenning N, Martins WP. Endometrial injury in women undergoing in vitro fertilisation (IVF). Cochrane Database Syst Rev 2021; 6: CD009517.
 Metwally M, Chatters R, White D, Hall J, Walters S. Endometrial scratch in women undergoing first-time IVF treatment: A systematic review and meta-analysis of randomized controlled trials. Reprod Biomed Online 2022; 44: 617–629.
 Vitagliano A, Di Spiezio Sardo A, Saccone G, Valenti G, Sapia F, Kamath MS, et al. Endometrial scratch injury for women with one or more previous failed embryo transfers: A systematic review and meta-analysis of randomized controlled trials. Fertil Steril 2018; 110: 687–702.
 Noori N, Ghaemdoust F, Ghasemi M, Liavaly M, Keikha N, Dehghan Haghighi J. The effect of endometrial scratching on reproductive outcomes in infertile women undergoing IVF treatment cycles. J Obstet Gynaecol 2022; 42: 3611– 3615.
 Lensen S, Osavlyuk D, Armstrong S, Stadelmann C, Hennes A, Napier E, et al. A randomized trial of endometrial scratching before in vitro fertilization. N Engl J Med 2019; 380: 325–334.
 Metwally M, Chatters R, Pye C, Dimairo M, White D, Walters S, et al. Endometrial scratch to increase live birth rates in women undergoing first-time in vitro fertilisation: RCT and systematic review. Health Technol Assess 2022; 26: 1–212.
 Zarei A, Alborzi S, Dadras N, Azadi G. The effects of endometrial injury on intrauterine insemination outcome: A randomized clinical trial. Iran J Reprod Med 2014; 12: 649–652.
 Mak JSM, Chung CHS, Chung JPW, Kong GWS, Saravelos SH, Cheung LP, et al. The effect of endometrial scratch on natural-cycle cryopreserved embryo transfer outcomes: A randomized controlled study. Reprod Biomed Online 2017; 35: 28–36.
 Eskew AM, Reschke LD, Woolfolk C, Schulte MB, Boots CE, Broughton DE, et al. Effect of endometrial mechanical stimulation in an unselected population undergoing in vitro fertilization: Futility analysis of a double-blind randomized controlled trial. J Assist Reprod Genet 2019; 36: 299–305.
 Mackens S, Racca A, Van de Velde H, Drakopoulos P, Tournaye H, Stoop D, et al. Follicular-phase endometrial scratching: A truncated randomized controlled trial. Hum Reprod 2020; 35: 1090–1098.
 Tian Y, Huang J, Wang CC, Lin H, Huang X, Zhao Y, et al. The impact of endometrial scratch performed in mid-luteal phase on the endometrium whole genome transcriptomic profiles in following menstrual cycle. Hum Fertil 2023; 1–9.
 Yavangi M, Varmaghani N, Pirdehghan A, Varmaghani M, Faryadras M. Comparison of pregnancy outcome in intrauterine insemination-candidate women with and without endometrial scratch injury: An RCT. Int J Reprod BioMed 2021; 19: 457–464.
 Shahrokh-Tehraninejad E, Dashti M, Hossein-Rashidi B, Azimi-Nekoo E, Haghollahi F, Kalantari V. A randomized trial to evaluate the effect of local endometrial injury on the clinical pregnancy rate of frozen embryo transfer cycles in patients with repeated implantation failure. J Family Reprod Health 2016; 10: 108.
 Bui BN, Lensen SF, Gibreel A, Martins WP, Torrance H, Broekmans FJ. Endometrial injury for pregnancy following sexual intercourse or intrauterine insemination. Cochrane Database Syst Rev 2021; 3: CD011424.
 Mol BW, Barnhart KT. Scratching the endometrium in in vitro fertilization- time to stop. N Engl J Med 2019; 380: 391–392.