Abstract:Objective To investigate the ectopic pregnancy (EP) rate with fresh and frozen-thawed embryo transfers, and factors associated with ectopic pregnancy in patients undergoing in vitro fertilization and embryo transfer (IVF-ET). Methods A total of 3,028 patients who underwent IVF-ET or intra-cytoplasmic sperm injection and embryo transfer (ICSI-ET) in Xiangya Hospital from January 2013 to April 2015 were analyzed retrospectively. Of the 1,696 women with fresh IVF transfer cycles (fresh transfer group), 75 had an EP; while 49 of the 1,332 women with frozen-thawed transfer cycles (frozen-thawed cycle group) had an EP. The incidences of EP were compared between both groups and the influential factors of EP were investigated. Results The incidence of EP per clinical pregnancy for the frozen-thawed cycle group and the fresh transfer group was 3.7% and 4.4% respectively; the difference was not statistically significant. The ectopic pregnancy was associated with pelvic oviduct disease, history of EP, history of artificial abortion, endometrial thickness and type of infertility. Conclusions The ectopic pregnancy rate of frozen-thawed embryo transfer is not lower than that of fresh transfer in patients undergoing IVF-ET.