1. 2008/08/何積泓

3. Reproductive Aging A continuous process begins prior to birth A continuous process begins prior to birth The depletion of non-growing follicles (NGFs) The depletion of non-growing follicles (NGFs) Ovarian dysfunction occurs many years prior to menopause Ovarian dysfunction occurs many years prior to menopause Perimenopause: the number of remaining ovarian NGFs has dropped below a critical threshold Perimenopause: the number of remaining ovarian NGFs has dropped below a critical threshold

4. Menopause Average 51 ± 8 years Average 51 ± 8 years Initial endowment of NGFs Initial endowment of NGFs The rate of NGF depletion The rate of NGF depletion A model to better describe NGF depletion A model to better describe NGF depletion Previous model: the decay rate is exponential and biphasic (4 studies, n = 6 ~ 52) Previous model: the decay rate is exponential and biphasic (4 studies, n = 6 ~ 52)

5. Human ovaries Elective unilateral or bilateral oophorectomy (n = 45) Elective unilateral or bilateral oophorectomy (n = 45) Organ donation agencies or national tissue bank (n = 77) Organ donation agencies or national tissue bank (n = 77) Exclusion: chemotherapy, radiation, ovarian surgery, ovarian pathology, cyst > 2cm diameter Exclusion: chemotherapy, radiation, ovarian surgery, ovarian pathology, cyst > 2cm diameter

8. Linear model, R 2 = 0.50, 3.83M NGFs at birth, 2,290 NGFs at 51 y/o Linear model, R 2 = 0.50, 3.83M NGFs at birth, 2,290 NGFs at 51 y/o

9. Exponential model, R 2 = 0.46, 2.75M NGFs at birth, 3,881 NGFs at 51 y/o Exponential model, R 2 = 0.46, 2.75M NGFs at birth, 3,881 NGFs at 51 y/o

10. Biphasic exponential model, 1.15M NGFs at birth, 1,071 NGFs at 51 y/o Biphasic exponential model, 1.15M NGFs at birth, 1,071 NGFs at 51 y/o

11. Power model, log(NGF#)=a(age) b +c, R 2 =0.84 0.52M NGFs at birth, 758 NGFs at 51 y/o Power model, log(NGF#)=a(age) b +c, R 2 =0.84 0.52M NGFs at birth, 758 NGFs at 51 y/o

12. Discussion Previous exponential and biphasic model is unrealistic Previous exponential and biphasic model is unrealistic Power model is simpler and better Power model is simpler and better The NGF depletion is constantly accelerating The NGF depletion is constantly accelerating 84% variability in NGF count is explained by age 84% variability in NGF count is explained by age Other clinical markers may improve the predictive power Other clinical markers may improve the predictive power