Effect of Comprehensive Individualised Interventions on the Clinical Outcomes of Patients With Recurrent Implantation Failure: A Single‐Centre Retrospective Cohort Study

ABSTRACT Objective The objective of this study is to evaluate the impact of comprehensive individualised interventions on the clinical outcomes of patients with recurrent implantation failure (RIF), as few studies have evaluated their effectiveness. Design Retrospective cohort study. Setting Tertiary hospital, from June 2016 to December 2022. Population Overall, 1546 patients with RIF underwent endometrial biopsy during implantation. Methods The comprehensive individualised interventions were conducted on the basis of the endometrial histological dating, endometrial CD138 count, endometrial immune‐cell proportion and endometrial microbiota testing. Main Outcome Measures Cumulative ongoing pregnancy rate (cOPR). Results The median number of failed transfer cycles was 3 (range, 2–12), and the cOPR was 58.0%. The rates of window of implantation (WOI) displacement, CD138 positivity, imbalanced endometrial immune‐cell proportion, endometrial microbiota testing, multiple factors and unexplained RIF were 34.0%, 9.3%, 7.5%, 4.1%, 32.4% and 12.7%, respectively. The cOPRs of the individualised frozen embryo transfers in patients having RIF with WOI displacement, WOI CD138 positivity, imbalanced endometrial immune‐cell proportion, endometrial microbiota testing, multiple factors and unexplained RIF were 64.1%, 57.6%, 55.1%, 38%, 64.2% and 34.5%, respectively. After adjusting for basic characteristics through logistic regression analysis, the cOPRs of the WOI displacement group, WOI CD138 positive group and immune‐cell proportion imbalanced group remained higher than that of the unexplained RIF group. However, the cOPR was comparable between the endometrial microbiota testing and unexplained RIF groups. Conclusion Comprehensive individualised interventions may improve clinical outcomes for patients with RIF, warranting further investigation.