Human ovarian reserve from conception to the menopause.
Level 4 - case-series / case-control
Mathematical modeling of pooled cross-sectional histological data from eight separate studies
PubMed 20111701 · doi:10.1371/journal.pone.0008772
What was done
Researchers modeled the age-related decline of human non-growing follicle (NGF) populations from conception to menopause. They compiled data from eight published quantitative histological studies encompassing 325 ovarian samples spanning ages from 7 weeks post-conception to 51 years (median age 32 years). The dataset was evaluated across 20 peak function models, selecting the best-performing model based on the correlation coefficient (r2).
What was found
A five-parameter asymmetric double Gaussian cumulative (ADC) model provided the best fit for log-adjusted NGF counts across the lifespan (r2 = 0.81 overall; r2 = 0.95 when restricted to ages <=25 years), indicating that age accounts for 81% of the variance in ovarian reserve. The model estimates that for 95% of women, only 12% of the maximum pre-birth follicle population remains by age 30, and only 3% remains by age 40. Furthermore, the estimated rate of follicle recruitment increases from birth to approximately age 14, after which it steadily declines until menopause.
Why it matters
This model provides a foundational mathematical baseline for the human ovarian reserve trajectory across life, offering quantitative reference points for fertility counseling and reproductive aging.
Limits
The analysis relies on pooled historical cross-sectional tissue specimens rather than longitudinal observations in living individuals. True individual variation in initial follicle endowment and decline rates remains wide, and histological follicle counts do not directly measure functional reproductive capacity or oocyte quality.
Cited by
- supports A female fetus has 6 to 7 million eggs at 5 months of gestation, which decreases to 1 to 2 million at birth and to approximately 500,000 at menarche.