Impact of embryo replacement depth on in vitro fertilization and embryo transfer outcomes

ObjectiveTo investigate the impact of embryo replacement depth on IVF and embryo transfer outcomes.DesignRetrospective analysis (May 2005 to November 2008) of 5,055 ultrasound-guided embryo transfers belonging to 3,930 infertile couples. The distance between the fundal endometrial surface and the catheter tip was measured and accordingly, patients were divided into five groups.SettingAnatolia IVF Center, Ankara, Turkey.Patient(s)All patients enrolled in the IVF program undergoing embryo transfer.Intervention(s)No patient received any additional procedure or intervention.Main Outcome Measure(s)Clinical pregnancy rate (PR) and ongoing PR.Result(s)Mean total number of embryos transferred in groups 4 and 5 were significantly higher than in groups 2 and 3. Analysis of PRs and outcome of gestations in the five groups studied yielded similar PRs in all groups except for group 1.Conclusion(s)Pregnancy rates and ongoing PRs are higher if the embryos are replaced at a distance >10 mm from the fundal endometrial surface. In addition because significantly more embryos were replaced in cycles where the transfers occurred at a distance of >20 mm, a distance >10 mm to <20 mm seems to be the best site for embryo transfer to achieve higher PRs.