Ectopic pregnancy rates with day 3 versus day 5 embryo transfer: a retrospective analysis

BACKGROUND: Blastocyst transfer may theoretically decrease the incidence of ectopic pregnancy following IVF-ET in view of the decreased uterine contractility reported on day 5. The purpose of our study is to specifically compare the tubal pregnancy rates between day 3 and day 5 transfers. METHODS: A retrospective analysis of all clinical pregnancies conceived in our IVF program since 1998 was performed. The ectopic pregnancy rates were compared for day 3 and day 5 transfers. RESULTS: There were 623 clinical pregnancies resulting from day 3 transfers of which 22 were ectopic (3.5%). In day 5 transfers, there were 13 ectopic pregnancies out of 333 clinical pregnancies (3.9%). The difference between these rates is not statistically significant (P = 0.8). CONCLUSIONS: Our data suggests that the ectopic pregnancy rate is not reduced following blastocyst transfer compared to day 3 transfer. While there may be several benefits to extended culture in IVF, the decision to offer blastocyst transfer should be made independently from the issue of ectopic pregnancy risk.