Overview

This calculator combines two published models to predict the full IVF pipeline from antral follicles through live births. The baseline egg retrieval prediction comes from Herasight's SART-calibrated model; individual AMH, AFC, and FSH values adjust that baseline using coefficients from Han et al. 2022.

Step 1 — Baseline egg retrieval (Herasight)

The foundation is Herasight's zero-inflated negative binomial (ZINB) model for oocyte retrieval, trained on SART national outcomes data. We pre-compute median retrieved eggs for each age (18–46) and fertility profile. For example, a 30-year-old "Elective – Baseline" patient has a median prediction of 20 retrieved eggs. Profiles like endometriosis or tubal factor produce lower baselines (e.g. 14 eggs at age 30 for endometriosis).

Step 2 — Personalization via AMH / AFC / FSH (Han et al. 2022)

Han Y et al. (Frontiers in Endocrinology 2022;13:881983) built a multivariate negative binomial regression predicting oocyte yield from age, FSH, log(AMH), Inhibin B, and log(AFC) in 621 patients. We use their regression coefficients to calculate a relative adjustment factor:

adjustment = exp(
  0.398 × [ln(AMH) − ln(typicalAMH)]
+ 0.136 × [ln(AFC) − ln(typicalAFC)]   ← only when AFC is provided
− 0.024 × [FSH − typicalFSH]           ← only when FSH is provided
)

Final prediction: eggs = herasightBaseline(age, profile) × adjustment

Key design choice: Because these are partial-effect coefficients from a multivariate model, each one represents the independent effect after controlling for the others. When only AMH is available, we use only the AMH coefficient — not an estimated AFC derived from AMH, which would double-count AMH's signal through the AFC channel.

Step 3 — Antral follicle count projection

When AFC is not manually provided, the displayed follicle count is estimated from predicted eggs using the follicle-to-oocyte index (FOI):

displayAFC = predictedEggs / FOI(age)

Where FOI(age) ≈ 0.70, declining ~0.4% per year after age 30 (floor: 0.50). This ensures the Sankey always shows a biologically plausible downward flow — more follicles than retrieved eggs, reflecting non-responding follicles lost during stimulation.

When AFC is manually provided, it is used directly in both the Han adjustment and the Sankey display, and predicted eggs are capped at the AFC value (FOI ≤ 100%).

Step 4 — Downstream pipeline

Age-typical defaults

When the user provides only age, the model uses age-typical AMH values that align the adjustment factor to 1.0 (no change from the Herasight baseline). These represent a healthy IVF population, not the general population:

References

1. Herasight IVF Calculator — ZINB egg retrieval model calibrated to SART national data
2. Han Y, et al. "Prediction of oocyte yield based on a scoring system of ovarian reserve markers." Front Endocrinol. 2022;13:881983
3. SART National Summary Reports — live birth rates per euploid transfer