Predictive value of the time interval between embryo loading and transfer for IVF/ICSI success: a prospective cohort study

BACKGROUND The influence of embryo loading time (ELT) and the time interval between embryo loading and embryo transfer (TIEL-ET) on the success of IVF/ICSI is unknown. METHODS In a prospective cohort study, we aimed to ascertain the influence of ELT and TIEL-ET on ongoing pregnancy rate (OPR) and life birth rate (LBR). Data from 603 consecutive embryo transfers between January 2008 and December 2013 were collected. A complete data set including the outcomes of interest OPR and LBR was available for 410 women. The primary outcome was IVF/ICSI success, defined as OPR and LBR. RESULTS We used univariate and multivariate logistic regression for analysis. In a multivariate analysis, age (odds ratio [OR] 0.94; 95% confidence interval [CI] 0.89-0.99), catheter type (OR 0.45; 95% CI 0.24-0.84), and uterine length (OR 1.03; 95% CI 1.01-1.06), but not ELT and TIELT-ET were independently associated with OPR. Regarding LBR, age (OR 0.93; 95% CI 0.88-0.98), catheter type (OR 0.41; 95% CI 0.22-0.79), and uterine length (OR 1.03; 95% CI 1.01-1.06), but not ELT and TIELT-ET were independent predictors. CONCLUSION We conclude that speed of embryo transfer is not critical for the success of IVF/ICSI. However, care should be taken to choose catheter types proven to be associated with a high success rate.