IVF Outcome Simulator

Simulation model: All cycles assume PGT-A and single embryo transfer. Count-based rates (maturation, fertilization, blast utilization, euploid) use a unified distribution parameterized by mean, SD, and dropout rate. Pass/fail events (stim cancellation, thaw survival, positive beta, biochemical, miscarriage, burnout) use flat probabilities. Transfer model: positive beta → biochemical pregnancy check → miscarriage check → live birth. If an embryo does not survive the thaw, the next available euploid embryo is warmed in the same transfer cycle. Maximum 4 FET attempts per retrieval within a 2-year calendar window. Simulation runs 25 iterations of 100,000 patients to produce 95% confidence intervals.

Beta distribution is the standard choice for modeling rates and proportions. It is naturally bounded between 0 and 1, meaning every sampled patient rate is a valid probability without any artificial clamping. The Beta distribution can be asymmetric — when the mean is far from 50%, the distribution skews appropriately (e.g., a mean of 80% produces a left-skewed shape with a longer tail toward lower values). This better reflects clinical reality where most patients cluster near the lab average but a minority may have notably worse outcomes. Recommended for most use cases.

STEP	PATIENT VARIABILITY (SD)	DROPOUT RATE (%)
STIMULATION
Stim cancellation rate % of intended retrievals cancelled before egg retrieval	—	—
LAB
Average oocytes retrieved Mean total oocytes per retrieval; SD captures patient variability; dropout = zero-egg retrieval rate
Maturation rate MII oocytes / total oocytes retrieved (%)
Fertilization rate 2PN embryos / MII oocytes inseminated (%)
Blast utilization rate Usable blastocysts / total 2PN embryos (%)
Euploid rate (PGT-A) Euploid blastocysts / biopsied blastocysts (%)
TRANSFER — SINGLE EMBRYO TRANSFER, MAX 4 FET WITHIN 2 YEARS
Cryopreservation thaw survival rate % of vitrified embryos surviving the warm; if failed, next embryo warmed same cycle	—	—
FET positive beta rate Positive hCG / FET performed (%)	—	—
Biochemical pregnancy rate % of positive betas that are biochemical only (no heartbeat)	—	—
Miscarriage rate Pregnancy loss following confirmed fetal heartbeat (% of clinical pregnancies)	—	—
Patient burn out rate % of patients who discontinue after each failed FET while embryos remain	—	—

Simulation Results — 25 × 100,000 patients

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Cumulative Live Birth Rate per Retrieval

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Avg FET Cycles per
Patient Reaching Transfer

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Avg Euploid Embryos
Banked

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% Exhausted Embryos
Without Live Birth

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% Ran Out of
Calendar Time

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% Live Birth
on FET 1

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% Live Birth
on FET 2

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% Live Birth
on FET 3

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% Live Birth
on FET 4+

PATIENT PATHWAY STAGE	N PATIENTS	% OF STARTED	% PREV STAGE	AVG COUNT	RETENTION