Bologna vs. POSEIDON criteria as predictors of the likelihood of obtaining at least one euploid embryo in poor ovarian response: an analysis of 6,889 cycles.

Objective: To study the likelihood of obtaining at least 1 euploid embryo for transfer in poor ovarian response (POR) diagnosed per Bologna and Patient-Oriented Strategies Encompassing IndividualizeD Oocyte Number (POSEIDON) criteria, and compare it between groups and with patients without POR.

Design: Retrospective cohort study.

Patients: Women undergoing an ovarian stimulation cycle with intention to pursue preimplantation genetic testing for aneuploidy.

Interventions: Bologna criteria and the POSEIDON classification system were applied to characterize each stimulation cycle as POR or not. Cycles identified as POR by POSEIDON were subdivided into groups I, II, III, and IV as defined by this classification system.

Main Outcome Measures: The proportion of cycles resulting in at least 1 euploid blastocyst. Other outcome measures included cycle yields (metaphase II oocytes, fertilized oocytes, blastocysts, and euploid blastocysts), and euploidy rate per embryo cohort.

Results: A total of 6,889 cycles were included, of which 3,653 (53.0%) were classified as POR per POSEIDON criteria: 1.5% (100/6,889) in group I, 3.2% (222/6,889) in II, 11.9% (817/6,889) in III, and 36.5% (2,514/6,889) in IV. Per Bologna criteria, 23.4% (1,612/6,889) of cycles were classified as POR. Group I had similar likelihood of obtaining at least 1 euploid embryo (97.0%; 95% confidence interval, 91.5%-99.2%) as cycles not deemed POR (91.9%; 95% confidence interval, 90.9%-2.8%), whereas this decreased significantly with each subsequent POSEIDON group (II: 77.9%, 72.0%-82.9%; III: 70.5%, 67.3%-73.5%; IV: 44.8%, 42.9%-46.7%) and those meeting Bologna criteria had the lowest rates (31.9%, 29.7%-34.3%). Cycle yields correlated with ovarian reserve testing results, whereas euploidy rates were associated with age.

Conclusions: Although younger POSEIDON groups (I and III) have higher euploidy rates than older groups (II and IV), each incremental POSEIDON group poses a higher risk of having no euploid blastocysts; with POSEIDON I being no different from non-POSEIDON, and Bologna having the worst prognosis. Although ovarian reserve appears to have little impact on euploidy rates, it remains a key prognostic factor for having at least 1 euploid embryo available for transfer through its impact on oocyte yield. To our knowledge, this is the first study to provide the odds ratio of this outcome depending on the degree of POR.