Blastocyst culture and transfer increases the efficiency of oocyte donation

Objective: To determine the impact of blastocyst transfer on an oocyte donation program. Design: Retrospective review of embryo transfer in an IVF clinic. Setting: Private assisted reproductive technology unit. Patient(s): Two hundred and twenty nine patients undergoing oocyte donation. Intervention(s): Culture of pronucleate embryos to either day 3 or day 5 Followed by embryo transfer. Main Outcome Measure(s): Implantation rates, pregnancy rates, and multiple gestations were analyzed. Result(s): Implantation rates and pregnancy rates were significantly increased by moving to extended embryo culture and transfer on day 5. After day 3 transfers, implantation and pregnancy rates were 47.1% and 75%, respectively. In contrast, on day 5 these rates were increased to 65.8% and 87.6%, Concomitantly, there were significantly fewer embryos transferred on day 5 (2.1) compared to day 3 (3.2). Conclusion(s): Blastocyst transfer is a highly effective treatment for patients who receive donor oocytes, allowing excellent pregnancy rates while significantly reducing the incidence of high-order multiple gestations. (Fertil Steril(R) 2000.74:482-6. (C) 2000 by American Society for Reproductive Medicine.).