The interovarian variation in three-dimensional ultrasound markers of ovarian reserve in women undergoing baseline investigation for subfertility

Objective: To evaluat differences in the three-dimensional (3D) ultrasound markers of ovarian reserve between the ovaries within an individual undergoing investigation for subfertility. Design: Prospective observational study. Setting: University-based assisted conception unit. Patient(s): Two hundred seventy women undergoing baseline early follicular phase ultrasound as an investigation for subfertility. Intervention(s): Three-dimensional ultrasound scan in early follicular phase between days 2 and 5 of the menstrual cycle. Main Outcome Measure(s): Variations in 3D ultrasound markers of ovarian reserve between the two ovaries within same individual. Result(s): Two hundred fifteen subjects were analyzed for ovarian volume and antral follicle count, and 205 subjects for 3D power Doppler indices. Significant differences were noted (median, range) in the number of antral follicles measuring >6.0 mm and ovarian volume. Significant correlation was noted between the two ovaries in antral follicles measuring 6.0 mm or less, ovarian volume, and 3D power Doppler indices. On stratifying the antral follicles according to size using sonography-based automated volume calculation with postprocessing, maximum variation was seen in follicles measuring more than 6.0 mm as measured using limits of agreement. Conclusion(s): There are significant differences in the antral follicles measuring >6.0 mm and ovarian volume, as measured using 3D ultrasound, that require consideration when comparing the two ovaries within an individual. (Fertil Steril(R) 2011;95:667-72. (C) 2011 by American Society for Reproductive Medicine.)