Ectopic pregnancy after assisted reproductive technology: what are the risk factors?

PURPOSE OF REVIEW: This review discusses recent publications that investigate risk factors associated with ectopic pregnancy after IVF. RECENT FINDINGS: Data on the risk factors for developing ectopic pregnancy after IVF are still inconsistent. Between fresh nondonor IVF and embryo transfer cycles, the significant risk factor for ectopic pregnancy was tubal factor infertility, and endometriosis, rather than male factor infertility. Higher ectopic pregnancy rate could be associated with zygote intrafallopian transfer, assisted hatching, large embryo transfer volume, deep fundal transfer, and frozen embryo transfer. The supraphysiologic progesterone level may decrease uterine contractility and enhance implantation in the uterine cavity in fresh embryo transfer compared with frozen embryo transfer cycles. Although recent results suggest reassurance in risk of ectopic pregnancy with frozen transfer, clinicians should be remembering this possibility while performing a frozen embryo transfer. Higher implantation potential per embryo at the blastocyst stage may increase the risk of ectopic pregnancy than cleavage stage. Especially, according to numbers of embryos transferred, different risk of ectopic pregnancy after IVF was noted. SUMMARY: Different hormonal milieu, the reproductive health characteristics of infertile women such as distorted tubal function, technical issues of IVF procedures, and the estimated embryo implantation potential are possible risk factors. How each factor contributes to the risk of occurring ectopic pregnancy after assisted reproductive technology is uncertain and needs further investigation.