The predictive value of the automated quantification of the number and size of small antral follicles in women undergoing ART.

BACKGROUND Sono-automatic volume calculation (SonoAVC) automatically identifies and measures the dimensions of hypoechogenic areas within datasets acquired using three-dimensional ultrasound. The objective of this study was to evaluate the predictive value of automated antral follicle counts according to their relative sizes in women undergoing assisted reproduction treatment (ART). METHODS A total of 156 subjects aged < or =40 years with a baseline FSH < or =15 IU that undergo their first cycle of ART were prospectively recruited. SonoAVC was used to measure the datasets and record the number of antral follicles measuring < or =9 mm in diameter. These follicles were then grouped into subsets according to their relative sizes: < or =2.0, 2.1-4.0, 4.1-6.0, 6.1-8.0 and 8.1-9.0 mm. The primary outcome was viable pregnancy confirmed on ultrasound 5 weeks following embryo transfer. RESULTS A total of 142 subjects were included for analysis of primary end-point. Those subjects who conceived had significantly more antral follicles measuring < or =2 (P = 0.041) and 2.1-4.0 mm (P < 0.001) than those who had unsuccessful treatment. There were no significant differences between the groups in the number of antral follicles measuring 4.1-6.0 (P = 0.191), 6.1-8.0 (P = 0.203) and 8.1-9.0 mm (P = 0.601). Multiple logistic regression showed that antral follicles measuring 2.1-4.0 mm were an independent predictor of pregnancy [Exp(B) = 1.234, 95% CI = 1.092-1.491; P = 0.004; AUC = 0.693]. CONCLUSION SonoAVC provides automated measures of antral follicle number and size. Using this technique, the number of antral follicles measuring 2.1-4.0 mm in diameter is an independent, significant predictor of pregnancy following in vitro fertilization treatment.