A practical method for ultrasonographically monitoring the day-to-day growth of individual ovarian follicles in women undergoing assisted reproduction

Abstract

The objective of this study was to validate the use of the nonidentity (NonID) method compared with the identity (ID) method for tracking the day-to-day growth of individual follicles in women undergoing ovarian stimulation for assisted reproduction. A retrospective observational study was conducted in 20 women during ovarian stimulation. Conventional 2-D transvaginal ultrasonography was used to monitor follicle growth every 2-3 days throughout stimulation. Video clips of both ovaries were obtained in sagittal and coronal planes at each visit. Standardized diameter measurements of all follicles ≥4 mm were made retrospectively from video clips. The growth profiles of all follicles that developed to ≥10 mm were determined using the ID and NonID methods. Using Lin's concordance statistics, we documented that agreement between methods was 91% for follicles <10 mm, 96% for follicles 10-15 mm and 99% for follicles >15 mm. Lin's concordance correlation coefficient between the two methods was 0.96 (standard error = 0.003). We concluded that the NonID method is a practical, effective tool for monitoring the day-to-day growth of individual ovarian follicles in women undergoing assisted reproduction.