Total number of oocytes and zygotes are predictive of live birth pregnancy in fresh donor oocyte in vitro fertilization cycles

Objective To evaluate the association of oocyte donor–recipient characteristics, oocyte donor response, and live birth pregnancy rate following fresh donor oocyte IVF-ET. Design Retrospective cohort study. Setting Academic reproductive medicine practice. Patient(s) Two hundred thirty-seven consecutive fresh donor oocyte IVF-ET cycles from January 1, 2007 to December 31, 2013 at the Massachusetts General Hospital Fertility Center. Intervention(s) None. Main Outcome Measure(s) Live birth rate per cycle initiated. Result(s) The mean (±SD) age of oocyte donors and recipients was 27.0 ± 3.7 and 41.4 ± 4.6 years, respectively. Oocyte donor demographic/reproductive characteristics, ovarian reserve testing, and peak serum E2 during ovarian stimulation were similar among cycles which did and did not result in live birth, respectively. Overall implantation, clinical pregnancy, and live birth pregnancy rates per cycle initiated were 40.5%, 60.8%, and 54.9%, respectively. The greatest probability of live birth was observed in cycles with >10 oocytes retrieved, mature oocytes, oocytes with normal fertilization (zygote–two pronuclear stage), and cleaved embryos. Conclusion(s) The number of oocytes (total and mature), zygotes, and cleaved embryos are associated with live birth following donor oocyte IVF cycles. These findings suggest that specific peri-fertilization factors may be predictive of pregnancy outcomes following donor oocyte IVF cycles.