How Our Model Works
A plain-language summary of the published model
Stochastic Modeling
The ovaries hold a reserve of dormant follicles that is used up over life. The model treats the signal that wakes each follicle as a random process, so it produces a range of possible timelines rather than one fixed date.
Clinical Inputs
The forecast uses antral follicle count, age, and standard clinical intake. Anti-Müllerian hormone (AMH) and other inputs are optional.
Uncertainty Stated Up Front
Each forecast shows the most likely timing together with a 90% prediction interval. Clinicians use it as one input into counseling.
Our Commitment to Rigor
- The model's structure comes from the biology of follicle depletion, published in peer-reviewed journals.
- Each validation analysis, with its endpoints and pass criteria, is written down and locked before any outcome is analyzed. The primary plan is pre-registered on OSF.
- Initial validation is complete. Final validation is in progress.
- Every forecast carries a prediction interval, so clinicians see the range as well as the most likely timing.
Research Publications
Peer-reviewed research behind LifeAhead's approach
Recapitulating human ovarian aging using random walks
PeerJ
Johnson J, Emerson JW, Lawley SD
Models the signal that decides when each dormant follicle starts to grow as a random walk. Across many simulated women, the resulting follicle loss reproduces the population distribution of age at natural menopause.
Mathematical recapitulation of the end stages of human ovarian aging
Science Advances
Lawley SD, Sammel MD, Santoro N, Johnson J
Extends the random-walk model to the menopausal transition. The same model conditions reproduce the population timing of both the menopausal transition and natural menopause.
On modeling ovarian aging and menopause timing
Bulletin of Mathematical Biology
Lawley SD, Santoro N, Johnson J
Places models of ovarian aging in one mathematical framework and corrects an error in a recently published model of menopause timing. Uses extreme value theory to derive the full distribution of menopause age and to trace where its variability comes from.
Modeling the extension of ovarian function after therapeutic targeting of the primordial follicle reserve
Human Reproduction Update
Johnson J, Emerson JW, Smith A, Medina K, Telfer EE, Anderson RA, Lawley SD
Reviews emerging therapies that slow follicle loss or add follicles, and models how each would change the duration of ovarian function across the population.
Validation Methodology
How the forecast is tested
Pre-Specified Analyses
Each validation analysis, with its endpoints and pass criteria, is written down and locked before any outcome is analyzed. The primary plan is pre-registered on OSF.
Retrospective Cohorts
Initial validation on retrospective cohorts is complete. Each cohort is analyzed and reported separately.
Final Validation
Final validation in large longitudinal cohorts is in progress. Topline metrics will be published with the Clinical Validation Report.
Research Roadmap
Where the work stands
Peer-Reviewed Model Publications
The follicle-depletion model and its extension to the menopausal transition were published in PeerJ (2022) and Science Advances (2024).
Initial Validation
Validation analyses were specified in advance, and initial validation is complete.
Final Validation
Final validation in large longitudinal cohorts is in progress, each analysis locked before any outcome is analyzed.
FDA De Novo Submission
LifeAhead is preparing a De Novo Class II submission to FDA CDRH.