IVF Outcome Comparisons Between Fresh Embryo Transfers and Embryo Banking Cycles With Subsequent Thawed Transfers Vary Between Good-, Intermediate- and Poor-prognosis Patients

Abstract Never investigated before in poor prognosis patients, we here determined how in vitro fertilization (IVF) outcomes after fresh embryo transfers compare to frozen-thawed transfers after embryo banking. Using data from our center’s anonymized electronic research data bank, we in a retrospective controlled observational study investigated IVF cycle outcomes of poor-prognosis infertility patients, utilizing autologous eggs, while utilizing donor-egg recipient cycles as controls for covariables. To accomplish statistically valid comparisons, 4 different pairings of 1st IVF cycles were utilized: (i) 127 fresh vs. 193 frozen donor recipient cycles; (ii) 741 autologous fresh unselected non-donor IVF cycles vs. 217 autologous frozen non-donor IVF cycles; (iii) 143 favorably selected autologous non-donor IVF cycles vs. the same 217 frozen autologous cycles non-donor; and (iv) 598 selected average and poor-prognosis autologous non-donor cycles vs. the same 217 frozen autologous non-donor cycles. Main outcome measures were pregnancies and live births. Even within poor-prognosis patients, patient selection to significant degrees impacted how fresh and frozen-thawed IVF cycles compared. Though embryo banking with delayed embryo transfer in best-prognosis patients marginally improved IVF outcomes, in unselected patients it had no effect on outcomes, while in poor-prognosis patients it adversely affected IVF outcomes. Unexpectedly, the study also discovered a previously unreported effect of recipient-age on miscarriage risk in donor-egg recipient cycles, which apparently is independent of age-associated increases in chromosomal abnormalities and, therefore, must have other causes. This study suggests that in poor-prognosis patient banking cycles should be considered contraindicated, in intermediate-prognosis patients they do not appear to change outcomes and, therefore, do not warrant additional costs from thaw cycles, leaving only good-prognosis patients as potential candidates for such a strategy.