Predictors of success after embryo transfer: Experience from a single provider

OBJECTIVE: Our goal was to examine the variables present at the time of emb ryo transfer and to determine their effects on the clinical pregnancy rate. STUDY DESIGN: All fresh and frozen embryo transfers during a 3-year period in a u niversity-based in vitro fertilization program were examined. Female age, p revious in vitro fertilization attempt, diagnosis, embryo number and qualit y, transfer technique, and presence of a clinical pregnancy were recorded f or each couple. Logistic regression analyses were performed both univariate ly and multivariately to determine the association between a clinical pregn ancy and the independent variables. RESULTS: All transfers during the study period were included in the analysi s. The four primary diagnoses were pelvic or tubal disease, male factor inf ertility, unexplained infertility, and endometriosis. The 46 frozen embryo transfers had a clinical pregnancy rate similar to that among the 159 fresh embryo transfers and were therefore included in the analysis. One variable was found to significantly affect the outcome, the number of high-grade em bryos placed. The presence of a previous failed embryo transfer tended to l ower the success rate for future attempts; however, this result did not rea ch statistical significance. The catheter type and the transfer difficulty did not affect outcome. CONCLUSION: The two most important variables for predicting a clinical preg nancy are a first-time transfer and the number of high-grade embryos placed . Neither the type of embryo transfer catheter used nor the diagnosis affec ted outcome. In this small sample difficult embryo transfers did not dimini sh the chance for a successful outcome.