McCulloh DH, Kutchukhidze N, Charkviani T, et al. - Researchers investigated if and how follicle size is associated with the quality of oocytes retrieved from them as judged by ability to achieve the blastocyst stage, blastocyst grades and blastocyst ploidy. Assessment of follicle sizes for oocytes was done both as diameters (mm) and as Z values (expressed as their size relative to the mean and standard deviation of that donor’s follicular cohort). They assessed 22 oocyte donors (ages: 24.5 ± 3.5 years) whose recipients would use ICSI for insemination in this study. Follicles were aspirated one-at-a-time to be certain that the aspirated oocyte was from the same follicle measured. An associated follicle size was reported in 317 oocytes (96.1%). Among the oocytes with follicle sizes, 255 (80.4%) had a polar body, and 60 (18.9%) were immature: 31 (9.8%) with a visible germinal vesicle and 29 (9.1%) with neither a polar body nor a visible germinal vesicle. Outcomes suggest a significant predictive value of follicle size for oocyte maturity and for the ability of a fertilized oocyte to become a quality blastocyst. However, there was no correlation of the ploidy of each quality blastocyst with the size of the follicle from which its oocyte was retrieved.