Age and the ovarian follicle pool assessed with transvaginal ultrasonography

OBJECTIVE: We tested whether transvaginal ultrasonography could detect the age-related decrease in follicle counts that has been observed in autopsy studies. STUDY DESIGN: Thirty-one healthy volunteers in three age groups (22 to 25, 30 to 33, and 39 to 42 years) underwent ultrasonography in the follicular and luteal phases of the menstrual cycle. At the conclusion of the study the 124 ovarian scans were randomly ordered and antral follicles ≥2 mm were counted by an evaluator unaware of age. Ordinary least-squares linear regression was used to estimate the associations of age with the total antral follicle count and with ln (1 + follicle count). RESULTS: The numbers of antral follicles ≥2 mm decreased by about 60% between 22 and 42 years. Age- related decreases were similar for both phases of the cycle and held for both smaller (2 to 3.5 mm) and larger (>3.5 mm) follicles. CONCLUSION: We hypothesize that ultrasonographically derived counts of follicles provide a measure of reproductive age that may help to predict age-related phenomena.