Simple Tools for Assessment of Ovarian Reserve (OR): Individual Ovarian Dimensions Are Reliable Predictors of OR

Abstract

Ovarian reserve (OR)—the oocytes and granulosa cells available for procreation—declines with advancing age and also in some premenopausal women under treatment for infertility who respond suboptimally to attempted ovarian stimulation. These women may be at risk of becoming menopausal at a younger age. Basal levels of follicle-stimulating hormone (FSH) are routinely used in clinical practice to assess OR. The investigators planned a prospective observational study at an academic infertility practice to learn whether transvaginal ultrasound measurements of ovarian length, width, and overall diameter compare well with OR status as estimated by measuring serum FSH levels in the early follicular phase of the cycle. The study population consisted of 69 premenopausal women presenting for the assessment and treatment of infertility. The commonest causes of infertility were anovulation, male factor, and (in 14% of cases) diminished OR. All 3 parameters of ovarian size declined significantly with advancing age. FSH levels correlated linearly and significantly with age. Increasing FSH levels, signifying declining OR, were associated with significant declines in mean ovarian width, length, and diameter. Compared to patients with other causes of infertility, those with reduced OR had significantly lower values for all ovarian dimensions. Multivariate linear regression analysis confirmed that all 3 ovarian measurements were independent predictors of FSH levels after adjusting for age, body mass index, smoking status, and history of anovulation. Ovarian width was the strongest predictor. Overall, the statistical models accounted for 24% to 27% of variability in serum FSH levels. These findings indicate that single ovarian dimensions, particularly width, reliably predict declining OR status in premenopausal infertile women.