Endometrial scratch injury before intrauterine insemination: Is it time to re-evaluate its value? Evidence from a systematic review and meta-analysis of randomized controlled trials.

Amerigo Vitagliano (IT), Marco Noventa (IT), Antonio Simone Laganà (IT), Shara Borgato (IT), Gabriele Saccone (IT), Attilio Di Spiezio Sardo (IT), Carlo Saccardi (IT), Salvatore Giovanni Vitale (IT), Petro Salvatore Litta (IT)

[Vitagliano] University of Padua, [Noventa] , [Laganà] , [Borgato] , [Saccone] , [Di Spiezio Sardo] , [Saccardi] , [Vitale] , [Litta]

Context: Systematic review and meta-analysis. Objective: To assess the impact of endometrial scratch injury (ESI) on the outcomes of IUI-stimulated cycles. Methods: The review was reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two reviewers performed the literature search and independently judged the methodological quality of studies included in meta-analysis using the Cochrane Collaboration's tool for bias risk assessment. The body of evidence was assessed using GRADE methodology. Patients: Infertile women undergoing one or more IUI-stimulated cycles. Interventions: Randomized controlled trials (RCTs) were identified by searching electronic databases. We included RCTs comparing ESI (i.e. intervention group) during the course of IUI-stimulated cycle (C-ESI) or during the menstrual cycle preceding IUI-treatment (P-ESI) with controls (no endometrial scratch). The summary measures were reported as odds ratio (OR) with 95% confidence-interval (CI). Main Outcome Measures: Clinical-pregnancy rate, ongoing-pregnancy rate, multiple-pregnancy rate, ectopic-pregnancy rate, miscarriage rate. Results: Eight trials were included in the meta-analysis, embedding a total number of 1871 IUI cycles. ESI was associated with higher clinical-pregnancy rate (OR 2.27; p < 0.00001) and ongoing-pregnancy rate (OR 2.04 p=0.004) in comparison to controls. No higher risk of multiple pregnancy (OR 1.09; p=0.88), miscarriage (OR 0.80; p=0.60) and ectopic pregnancy (OR 0.82; p=0.80) was observed in patients receiving ESI. Subgroup analysis based on ESI timing showed higher clinical pregnancy rate (OR 2.57) and ongoing pregnancy rate (OR 2.27) in patients receiving C-ESI and no advantage in patients receiving P-ESI. Conclusions: Available data suggest that ESI, performed once preferably during the follicular phase of the same cycle of IUI with the employ of flexible aspiration catheters, may improve clinical-pregnancy rate and ongoing-pregnancy rate in IUI cycles. ESI does not appear to increase the risk of multiple pregnancy, miscarriage and ectopic pregnancy.