Sibling embryo blastocyst development correlates with the in vitro fertilization day 3 embryo transfer pregnancy rate in patients under age 40

Objective: To examine the IVF day 3-ET pregnancy rate in patients under 40 with sibling embryo blastocyst development, compared with similar patients without blastocyst formation. Design: Retrospective analysis. Setting: Academic infertility center. Patient(s): One hundred twenty-five NF day 3-ET patients under 40 with sibl ing embryos for extended culture. Intervention(s): Extended culture of nontransferred sibling embryos for bla stocyst development. Main Outcome Measure(s): Pregnancy and multiple gestation rates, number of oocytes, embr yos formed, and embryos transferred. Result(s): Thirty-eight percent of patients became pregnant. Forty-eight pe rcent of patients had sibling embryos develop to blastocyst, The blastocyst group had more oocytes retrieved (17.4 +/- 6.6 versus 14.4 +/- 5.6), more embryos formed (11.2 +/- 4.2 versus 8.8 +/- 3.2), and a higher clinical pre gnancy rate (60% versus 18%) than the group without blastocyst development. Conclusion(s): Blastocyst transfer has been shown to improve implantation r ates and reduce the risk of multiple gestations from assisted reproductive technology. Sibling embryo blastocyst development may reflect superior embr yo quality, as manifested by increased IVF-ET pregnancy rates. in addition to predicting pregnancy in the current cycle, sibling embryo blastocyst dev elopment may provide information about the potential for fresh blastocyst t ransfer in subsequent cycles and help to identify patients at risk for mult iple gestations.