Analysis of factors related to embryo implantation/clinical pregnancy in patients with severe Intrauterine Adhesions(IUA) undergoing In Vitro Fertilization-Embryo Transfer (IVF-ET) following hysteroscopic adhesiolysis: a retrospective study

To investigate factors influencing embryo implantation and clinical pregnancy in patients with severe IUA undergoing IVF-ET and to develop a predictive model. This retrospective study analyzed 229 patients with severe IUA who underwent IVF-ET at Xiangtan Central Hospital between January 2020 and June 2024. All participants received transcervical resection of adhesions (TCRA) before embryo transfer. Clinical characteristics, endometrial repair protocols, medication types, and dosages were evaluated. Binary logistic regression was used to assess correlations between these factors and post-transfer embryo implantation or clinical pregnancy. The number of TCRA procedures emerged as a risk factor for both embryo implantation and clinical pregnancy. Additional risk factors for embryo implantation included years of infertility, initial and final American Fertility Society (AFS) scores, and the presence of endometrial cavity fluid (ECF). For clinical pregnancy, cumulative and daily average estrogen doses before transformation were identified as risk factors. Protective factors for both outcomes included endometrial thickness (EMT) on the day of transformation/ultrasound, regularly treat patients with CD138 positivity, and reduced endometrial peristalsis. Uterine artery resistance index (RI) and the use of a down-regulated hormone replacement therapy (HRT) protocol also favored embryo implantation, while transferring two high-quality embryos improved clinical pregnancy rates. Stepwise backward multivariate logistic regression was performed on variables with potential significance in univariate analysis. Using statistically significant variables, LightGBM prediction models were developed, yielding area under the curve (AUC) values of 0.892 for embryo implantation and 0.821 for clinical pregnancy. Severe IUA negatively impacts embryo implantation and clinical pregnancy. Optimizing clinical management—by minimizing TCRA frequency, reducing pre-transformation estrogen exposure, treating concurrent endometritis with antibiotics, suppressing endometrial peristalsis, and lowering uterine artery resistance—can enhance post-transfer outcomes. ECF adversely affects success rates, and while transferring more embryos may improve clinical pregnancy rates, it reduces implantation efficiency.