Egg yield vs. egg quality

To assess the correlation between donor oocyte yield and oocyte quality using a cryo-banking model. Retrospective study. Cryopreservation of donor oocytes derived from 543 egg retrievals was performed using minimum volume vitrification. All donors were treated with recFSH/GnRH antagonist/GnRH agonist trigger. Oocytes were warmed for each matched recipient independently (1334 recipient cycles, total of 8344 oocytes warmed). Outcome data was grouped by oocyte yield; I) <20 oocytes retrieved, II) 20-39 oocytes retrieved, III) ≥40 oocytes retrieved. Outcome parameters were analyzed by unpaired t-test or Chi-square test, as appropriate. Shown in the Table below.Tabled 1Group(# of oocyte yield at retrieval )I (<20)II (20-39)III (≥40)p value# of donor retrieval cycle92327115-E2 (mean±SD)2382±1325a3585±1902b4253±2711cp<0.05# of oocyte retrieved/Yield (mean±SD)1492 (16.22±2.52)a9555 (29.22±5.60)b5931 (51.57±12.01)cp<0.05Maturity/MII (%)1177(78.89)a7295(76.34)b4358(73.47)cp<0.05# of matched recipient176779379-# of MII oocyte warmed (mean±SD)1039(5.90±1.59)a4792 (6.13±1.61)a2513 (6.63±2.20)bp<0.05# survived (%)947 (91.14) a4435 (92.55) a2225 (88.54)bp<0.05# fertilized (%)821 (79.01) a3742 (78.08) a1846(73.46)bp<0.05# ET (mean±SD)277 (1.57±0.54)a1121 (1.44±0.53)b548 (1.45±0.55)bp<0.05#Clinical Pregnancy (%)107 (60.79)482 (61.87)227 (59.89)NS# Implantation (%)143 (51.62)595 (52.63)280 (51.09)NSa, b, c different superscripts within the same row indicates statistical difference. Open table in a new tab a, b, c different superscripts within the same row indicates statistical difference. The results demonstrated that the oocyte maturity rate was negatively correlated with the yield at retrieval. The survival and fertilization rate was lower when the yield of retrieved oocytes was above 40. However, the pregnancy and implantation rates were not significantly different among the three groups. Notably none of the donors developed ovarian hyperstimulation. The findings imply that cryo-egg banking can be performed safely and that though high egg yields are statistically worse for some egg quality parameters, the final outcome for recipients is not negatively affected.