Dr Dimitrios Mavrelos

Consultant in Obstetrics, Gynaecology and Reproductive Medicine

University College London Hospital

IVF cumulative live birth calculator

Estimates the cumulative chance of at least one live birth from a single egg collection, following the chain AFC → eggs collected → MII (mature) eggs → blastocyst → euploid blastocyst → live birth. Ovarian response is set from the antral follicle count (AFC) via the follicle–to–oocyte index (FOI); maturity, euploidy and blastulation are literature-based and adjustable.

Inputs

Total antral follicles (2–10 mm) on the baseline scan, both ovaries.
0.82
85%
40%
87%
0%
0% = informational only (numbers unchanged). Increasing it applies an evidence-based (Setti 2022) live-birth reduction that grows with maternal age.

Results (at selected blastulation rate)

Funnel — number at each stage

StageNumber95% CI
Antral follicle count (AFC)
Eggs collected
MII (mature) eggs
Blastocysts
Euploid blastocysts
Expected live births
Cumulative chance of ≥1 live birth
Cumulative chance of ≥2 live births
Cumulative chance of ≥3 live births

FOI & response band
Euploidy rate (age & dataset)
CPR per euploid (CARE 2025 data)

Sensitivity: blastulation per MII oocyte (25–55%)

Blast/MIIExpected euploidExpected live birthsCumulative P(≥1 LB)

Cycles to reach a target chance

90%
Egg collections needed
Egg collections≥1 live birth≥2 live births≥3 live births

References — AFC, FOI, oocyte maturity, euploidy & blastulation

Euploidy and per-euploid clinical pregnancy default to the clinic’s own Care London 2025 PGT-A audit (ref 1). Ovarian response is anchored to the follicle–to–oocyte index (FOI = oocytes retrieved ÷ AFC) of Alviggi/POSEIDON, with FOI >0.5 taken as normal ovarian sensitivity and ≤0.5 as suboptimal (hypo-) response. Band cut-offs use the POSEIDON 0.5 threshold and the 4,323-cycle tertiles (≤0.70 / 0.71–0.95 / 0.96–1.00). The default MII maturity (85%) is consistent with the ovarian-yield data (MII/AFC 0.68 vs oocytes/AFC 0.82 ≈ 83%). The age-based blastulation curve is expressed per MII oocyte, calibrated from the Fertility & Sterility usable-blastocyst-per-oocyte age data (35.7% at <30 → 14.5% at ≥43) at ~85% reference maturity, so that at 85% maturity the overall egg→blastocyst yield matches the prior version.

#Study / sourceDataset sizeKey finding
1Care London 2025 PGT-A audit (CAM meeting, 14 Jul 2026)1,804 biopsied blastocysts; 295 euploid transfers (2025, own eggs, excl. TBR)Euploidy by age 66.1% (<35) → 55.8% → 44.7% → 31.2% → 19.4% (>42); CPR per euploid transfer 63.7% overall (67.5% <35 … 54.4% 40–42; per-age samples small).
2Alviggi et al. FORT & FOI / POSEIDON, Front. Endocrinol. 2019Concept paperDefines FOI = oocytes retrieved ÷ AFC; FOI >0.5 = normal ovarian sensitivity, ≤0.5 = suboptimal response despite adequate reserve.
3FOI & clinical pregnancy, Front. Endocrinol. 20224,323 fresh transfer cyclesFOI tertiles ≤0.70 / 0.71–0.95 / 0.96–1.00; clinical pregnancy rises across bands (47.3% → 51.8% → 51.6%); +1 SD FOI → ~20% higher CPR.
4FORT & FOI by POSEIDON group, Front. Endocrinol. 202032,128 treatment cyclesMean FOI across POSEIDON groups 0.62–1.07; low ovarian sensitivity defined as FOI ≤0.50.
5Ovarian yield (oocytes & MII per AFC) & live birth, Front. Med. 2021Large IVF cohortOocytes/AFC 0.82 vs 0.71 and MII/AFC 0.68 vs 0.57 in live-birth vs no-live-birth groups; higher yield ratios predict live birth (implied MII maturity ≈ 83%).
6Mature oocyte proportion & IVF success, J Reprod Infertil2,565 ICSI cyclesLive birth 7.5% (≤50% MII) vs 21.5% (51–75%) vs 22.9% (76–100%); maturity >50% an independent predictor of pregnancy.
7Setti et al. 2022, Andrologia21,960 oocytes / 3,837 ICSI cyclesPaternal ageing independently impacts blastulation, interacting with maternal age.
8AI blastocyst prediction, Hum. Reprod. 202512,940 MII-oocyte images / 1,438 patientsBlastocyst rate per inseminated (MII) oocyte 50.0% autologous (age 36.5) vs 65.0% donor (age 26.6). (anchor for per-MII curve)
9Usable blastocyst dev. rate, Fertility & SterilityLarge extended-culture cohortUsable blastocyst rate per oocyte falls with age (35.7% <30 → 14.5% ≥43); ultra-low O₂ improves it. (anchor for age curve)
10Oocyte maturity multicenter study, J IVF-WorldwideMulticenter retrospectiveOocyte maturity (MII) rate is an age-independent predictor of blastocyst development and euploidy.
11Duke Fertility Center 2013–2017, MEFS Journal1,005 cycles / 11,022 oocytesOverall blastulation 70%; not sig. affected by maternal age; lower with surgical sperm (59.2%); physician effect up to 7.6%.
12Culture media & aneuploidy, PMC866 IVF cyclesSingle-step media: blastulation 51.7% vs 43.4% sequential (but higher aneuploidy).

Methods & assumptions

The calculator models a single egg collection as a chain and reports the cumulative chance of at least one live birth:

eggs = AFC × FOI;   MII = eggs × maturity;   P(≥1 live birth) = 1 − (1 − p)MII,   where   p = blastulationper MII × euploidy × live birth per euploid

  • AFC → eggs (FOI). The follicle–to–oocyte index (FOI = oocytes retrieved ÷ AFC) sets expected yield. In project mode you pick an FOI band (or fine-tune the FOI); in actual mode you enter the eggs collected and the FOI & band are computed. FOI >0.5 is normal ovarian sensitivity; ≤0.5 is a suboptimal/hypo-response despite adequate reserve (Alviggi/POSEIDON).
  • Eggs → MII. Only mature (metaphase-II) oocytes are fertilised and cultured. Maturity defaults to 85% (consistent with MII/AFC ≈ 0.68 vs oocytes/AFC ≈ 0.82) and is adjustable; outcomes fall sharply below ~50% maturity.
  • MII → blastocyst. Blastulation is expressed per MII oocyte. The age-based default is calibrated from the Fertility & Sterility usable-blastocyst-per-oocyte age data at ~85% reference maturity, so at 85% maturity the egg→blastocyst yield matches the prior version; it can be overridden manually.
  • Euploidy defaults to the Care London 2025 PGT-A audit by age band (66.1% <35 → 19.4% >42); CRGH 2016–18, Reprogenetics 2017 and their blend remain selectable.
  • Per-euploid outcome defaults to the Care London 2025 clinical pregnancy rate (63.7% all ages, or age-specific) converted to live birth by an adjustable live-birth-per-clinical-pregnancy factor (default 87%); a manual live-birth rate is also selectable. Per-age CPR samples are small, so the audit advises quoting the all-ages figure.
  • Paternal age is informational by default; the optional strength control applies a maternal-age-scaled reduction to the live-birth step (Setti et al. 2022) and does not alter euploidy, which is maternal in origin.

Key limitations: figures are population averages, not individual predictions; each MII oocyte is treated as statistically independent; FOI, maturity, euploidy and blastulation are modelled as independent multiplicative steps; embryo quality, mosaicism, endometrial and clinical factors are not modelled. Individual results vary considerably.

Disclaimer

This calculator provides an educational estimate only of the cumulative chance of at least one live birth from a single egg collection. It is based on published cohort data and fixed average assumptions (ovarian response by FOI, oocyte maturity, blastocyst formation, embryo euploidy by age, and live birth per euploid embryo transferred) and treats each mature egg as independent. It is not a personalised prediction and does not account for individual clinical circumstances, embryo quality, or laboratory-specific results. Actual outcomes vary considerably between patients. Always follow clinician advice.