Required number of blastocysts transferred, and oocytes retrieved to optimize live and cumulative live birth rates in the first complete cycle of IVF for autologous and donated oocytes.

Purpose: To investigate live birth rate (LBR) and cumulative live birth rate (CLBR) to achieve the first newborn per blastocyst transferred and oocyte retrieved in the first complete IVF cycle of autologous and donated oocytes and identify the possible success factors.

Methods: This was a retrospective cohort study of a private IVF center. There were 1867 cycles, 1241 of which were fresh transfers and 626, their subsequent thawing transfers.

Results: We found significant variables by binary logistic regression. For LBR, female infertility and the day of blastocyst transferred were relevant; however, for CLBR, the numbers of blastocysts available for future transfers, oocyte age, and maternal age were more critical. Oocyte age is a negative factor that begins to affect CLBR gradually beyond 36 years; from that age, there are significant worse results in polycystic ovary syndrome and poor responder patients.

Conclusion: The LBR and CLBR were optimized for oocyte recipients when eight oocytes were retrieved (63.6%; 87.9%); at most, fourteen oocytes should be assigned to avoid freezing surplus blastocysts. Thirteen autologous oocytes (69.2%; 92.3%) were ideal for optimization. CLBR optimized after three blastocysts in donor oocytes (81.8%) and four for autologous oocyte patients (80.9%). Our outcomes are valuable for doctors and infertile couples, and they give us information on what we can expect from a first complete IVF cycle.