Risk Factors of Ectopic Pregnancy in Women Undergoing In Vitro Fertilization and Embryo Transfer (IVF-ET).

To identify risk factors associated with ectopic pregnancy (EP) in women undergoing assisted reproductive technology (ART).A retrospective study was conducted among pregnant women after in vitro fertilization and embryo transfer (IVF-ET) in an assisted conception unit of a university hospital between 1994 and 2013. The factors evaluated included the use of donor oocyte, use of intracytoplasmic sperm injection (ICSI), stage of embryo, number of embryos transferred, and fresh or frozen-thawed cycle.One thousand three hundred eighty five pregnancies were identified of which 29 were ectopic pregnancies. Embryo transfer (ET) in fresh cycle significantly increased risk for EP compared with frozen-thawed cycle (p = 0.005). Day-5 ET also significantly increased higher EP risk than day-3 ET (p = 0.041). Three or more embryos transfer (p = 0.085), use of donor oocyte (p = 0.999), and use of ICSI (p = 0.246) did not significantly influence EP risk.Embryo transfer in fresh cycle and day-5 embryo transfer significantly increased EP risk. More patients and embryo characteristics are necessary to be studied to identify more valid predictors.