Variability of ovarian follicular growth in natural menstrual cycles.

Variation of ovarian follicular growth has been found to be too great for conventional statistical methods to provide valuable information when this growth has been related to menstrual age or peak volume day. A method that relates follicular growth to its start (follicular growth age) is presented. With the use of this dating method, variability of follicular growth was found to be within limits that could be handled by simple methods. Follicular volume growth followed a sigmoid-shaped curve and was well described by our growth equation.