Blastocyst-stage transfer of poor-quality cleavage-stage embryos results in higher implantation rates

Objective: To determine the feasibility and success of blastocyst-stage emb ryo transfers in patients having only fair and poor quality cleavage-stage embryos on day 3. Design: Prospective case study with historic controls. Setting: Tertiary care private hospital IVF center. Patient(s): A total of 158 day 5 embryo transfer cycles in patients with gr ade 3 and grade 4 cleavage-stage embryos. Control group consisted of 162 da y 3 transfer cycles performed with embryos of similar quality. Intervention(s): In vitro culture of embryos up to the blastocyst stage. Main Outcome Measure(s): The percentage of cycles that culminated in the tr ansfer of at least one blastocyst and implantation and pregnancy rate relat ed to the day of transfer. Result(s): In the day 3 transfer group, a mean of 5.2 embryos were replaced per patient. This was significantly more than the mean of 2.4 embryos that could be replaced on day 5 (P (.001). The clinical pregnancy rate per embr yo transfer was 27.2% and 33.5% in the two groups, respectively (P >.05). T he implantation rate per embryo was significantly higher in the day 5 trans fer group (15% vs. 5.9%). The multiple pregnancy and abortion rates were si milar between the groups. Conclusion(s): Transfer of fair and poor quality embryos at the blastocyst stage is feasible and is associated with higher implantation rates as compa red to transfer of similar quality embryos on day 3. (C) 2001 by American S ociety for Reproductive Medicine.