Finding (UK HFEA registry, 156,947 women / 257,398 cycles): Prognosis-adjusted cumulative LBR for women aged 40–42 rises 12.3% (cycle 1) → 19.8% (cycle 2) → 24.7% (cycle 3) → 28.0% (cycle 4) → 29.7% (cycle 5) → 31.5% (cycle 6). Cycles include all fresh + frozen transfers from each retrieval. For women >42, per-cycle rates stay below 4%.
Finding (Japanese specialty clinic, n=1,011 age 40–48): 2-year CLBR by age: 40 → 55.6%, 41 → 39.0%, 42 → 31.3%, 43 → 19.1%, 44 → 10.6%. ~80% of live births at age 40–42 occurred by the 4th transfer. At age 40, median AMH 1.63 in live-birth group vs 1.13 in no-live-birth group (p=0.005). My AMH 1.30 sits between these medians = mid-population at age 40. Caveat: this is a top-tier private clinic — likely upper-bound estimate.
Finding (DOR-only cohort, AMH <1.1 and AFC ≤6, 343 patients): Among women aged ≥40 with DOR, CLBR after 6 cycles is 14.7% (conservative) to 26.0% (optimistic). The CLBR curve plateaus at cycle 4 at 13.8%. Authors conclude "more than 4 cycles may have limited benefit" for age 40+ DOR. My AMH 1.30 sits just above their DOR threshold (1.1); my AFC 6 meets their threshold — I'm on the borderline.
| Sub-question | Evidence-based answer |
|---|---|
| Per-cycle LBR, cycle 1, age 40 | ~12–13% (UK HFEA, 40–42 bucket) |
| CLBR after 2 cycles | ~20% (HFEA) |
| CLBR after 3 cycles | ~25% (HFEA central estimate) |
| CLBR after 4 cycles | ~28% — plateau begins |
| Where does the curve plateau? | Cycle 4 (consistent across HFEA, Xi 2025, Khalife 2020, Seifer SART 2023) |
| Effect of my prior natural live birth (2024) | None at age 40+ (Kalu 2011). At younger ages it predicts IVF success; at 40+ the new obstacle is oocyte quality, not the original implantation issue. |
| AMH 1.30 / AFC 6 stratification | Mid-population for age 40 (Nukaga); borderline DOR by Xi's definition. Sits between the optimistic (HFEA) and pessimistic (Xi DOR-only) bands. |
| Realistic ceiling for 2–3 cycles at my profile | 20–30% CLBR, central estimate ~25%. Downside ~15% (DOR cohort), upside ~40%+ (top-tier clinic). |
I have flights booked for May 23 → Nov 18, 2026 in Hungary, with retrievals planned at Repromeda (Brno) or another CZ clinic. That gives me ~6 months for 2–3 retrieval cycles. The evidence-based message: cycles 1–3 are the high-yield window; cycle 4 is where marginal benefit starts to flatten. By the time I'd be considering a 5th or 6th cycle (likely 2027+), per-cycle returns are diminishing fast.
| Finding | Confidence | Note |
|---|---|---|
| Realistic CLBR ~20–30% after 3 cycles | High | Multiple converging sources; HFEA registry-level data. |
| The curve plateaus at cycle 4 | High | Consistent across HFEA, Xi 2025, Khalife 2020, Seifer 2023. |
| My prior natural live birth doesn't boost IVF prognosis | Medium | Kalu 2011 single-clinic UK cohort; counter-intuitive but consistent with age-driven oocyte quality model. |
| I'm mid-population for age 40, not lower-end | Medium | Nukaga 2024 stratification by AMH. Japanese cohort — may not generalize perfectly. |
| Top-tier clinics outperform national averages | Medium | Nukaga 55.6% vs HFEA 12.3% gap is partly clinic quality. |