Ectopic pregnancy rates in frozen versus fresh embryo transfer in in vitro fertilization: A systematic review and meta-analysis

Objective: To evaluate whether the rate of ectopic pregnancy differs between fresh and frozen embryo transfers. Design: Systematic review and meta-analysis. Setting: Centers for reproductive care. Materials and methods: An electronic literature search in MEDLINE through PubMed was performed through December 2013. We included clinical trials comparing outcomes of in vitro fertilization (IVF) cycles between fresh and frozen embryo transfers. Main outcome measures: Ectopic pregnancy rates from fresh versus frozen IVF cycles. Results: A meta-analysis revealed no significant difference between ectopic pregnancy rates in fresh versus frozen embryo transfer. Similarly, there was no difference between ectopic pregnancy rates in natural-cycle frozen embryo transfer versus programmed cycles. Conclusions: Differences in the hormonal milieu of the uterine environment between fresh and frozen embryo transfer stimulation do not appear to affect the ectopic pregnancy rate. More directed studies are needed before a definite recommendation can be made as to which is safer for prevention of ectopic pregnancy– fresh or frozen embryo transfer