RESUMEN
OBJECTIVE: Embryo transfer is a critical step in assisted reproduction. However, the different aspects of the procedure were not fully estimated. The aim of this study is to evaluate the impact of each aspect in the procedure to success of pregnancy. METHODS: Medical records of 525 fresh IVF/ICSI cycles were reviewed retrospectively. All embryo transfers were performed under ultrasonography guidance and after removal of cervical mucus. Assessed primary variables are difficulty of procedure (easy, moderate, and difficult), presence of blood in the catheter, types of catheter (soft or hard) and physician factor, and confounding variables are age of patient, total number of oocytes, number of transferred embryos, the highest grade of embryo, endometrial thickness. Measured outcomes were clinical pregnancy (visible fetal heart beat by ultrasonography) and live-birth rate. Univariate analysis and multivariate analysis by logistic regression test were used. RESULTS: Among the variables of embryo transfer procedure, the difficulty of procedure was the only significant factor influencing both clinical pregnancy (OR: 0.402, 95% CI: 0.205-0.789, easy vs. moderately difficult) and live birth rate (OR: 0.380, 95% CI: 0.178-0.841, easy vs. moderately difficult). The difference between moderately difficult and very difficult procedure was not significant. Presence of blood was significant for live-birth rate (OR: 0.512, 95% CI: 0.267-0.980). Types of catheter and physician factor were not significant factors. CONCLUSION: The difficulty of the transfer procedure and presence of blood in catheter are significant factors influencing ART outcome.