Early compaction on day 3 may be associated with increased implantation potential

ObjectiveTo determine whether day 3 embryos exhibiting early compaction have an improved implantation potential compared to embryos without compaction.DesignA retrospective cohort study.SettingHospital-based academic medical center.Patient(s)Women <38 years of age undergoing IVF cycles between November 2001 and December 2004 having a day 3 transfer of one or two embryos with >8 cells.Intervention(s)Standard IVF protocol.Main Outcome Measure(s)Compaction grading and implantation rates of 1,047 embryos as related to fragmentation of ≥ 8-cell embryos in patients with either 0% or 100% implantation.Result(s)Compaction grading was strongly associated with implantation potential; however, the direction of this effect depended on the degree of fragmentation. In embryos with <10% fragmentation, implantation rates increased with the degree of compaction (grade 1, 25%; grade 2, 33%; and grade 3, 47%); in embryos with ≥10% fragmentation, the effect was reversed (grade 1, 38%; grade 2, 20%; and grade 3, 9%).Conclusion(s)Assessing the degree of compaction can be a valuable addition to traditional morphologic assessment in identifying optimal embryos for transfer on day 3.