Day 2 transfer improves pregnancy outcome in in vitro fertilization cycles with few available embryos

ObjectiveDelaying ET to day 3 to optimize embryo selection is well accepted. However, in cases where there are not enough embryos to perform selection, it is not clear whether there is a difference in clinical outcomes with the day of ET.DesignCohort study.SettingAcademic medical center.Patient(s)Two hundred forty-two fresh IVF/intracytoplasmic sperm injection (ICSI) cycles from 2002–2004, where all generated embryos were transferred irrespective of quality because of an extremely low number of available embryos.Intervention(s)In time period 1, ET was on day 3. In time period 2, ET was on day 2.Main Outcome Measure(s)Patient response to stimulation was analyzed along with pregnancy outcome and implantation rate.Result(s)Miscarriage rates were decreased, and ongoing pregnancy rates were increased with a day 2 ET in patients <40 years of age.Conclusion(s)In women <40 years of age, the day of transfer is a significant predictor of clinical outcome in cases in which a low number of embryos are available for transfer. The evidence suggests that limiting embryo culture to only 2 days reduces the incidence of miscarriage and increases ongoing pregnancy rates.