Follicular Volume Predicts Oocyte Maturity: A Prospective Cohort Study Using Three-Dimensional Ultrasound and SonoAVC

The aim of this study was to investigate whether the automatic measurement of follicular volume by three-dimensional (3D) ultrasound can predict the number of mature oocytes retrieved. A prospective cohort study including 47 women undergoing in vitro fertilization was conducted in a private fertility center. Follicular growth was monitored both manually and automatically using 3D scanning with SonoAVC on the day of human chorionic gonadotropin (hCG) administration. Regression analysis showed that under a standard protocol for hCG administration, the count of mature oocytes is well predicted by a multivariate model including the counts of follicles in the volume classes 2.00 to 5.00 cm(3), 1.50 to 1.99 cm(3), 1.00 to 1.49 cm(3), and 0.60 to 0.99 cm(3). In conclusion, this study shows that follicular volume as measured by SonoAVC on the day of hCG administration can be useful to predict oocyte maturity. Specifically, larger follicles and smaller size follicles (class 0.60-0.99 cm(3)) contribute to the mature oocyte count. This finding warrants the design of clinical trials to establish new criteria for hCG administration based on follicular volume.