Search "IVF success rate" and you'll get a different number from every clinic, every article, and every forum post. That's not because the numbers are all lies — it's because "success rate" isn't one number. It's at least four different numbers, and clinics pick whichever one looks best.
Here's what the data actually shows, broken down by age, and how to read any number a clinic gives you.
Four different things people call "success rate"
- Pregnancy rate — a positive beta-hCG blood test. Includes pregnancies that later miscarry. The highest of the four numbers.
- Clinical pregnancy rate — a pregnancy confirmed on ultrasound with a heartbeat. Lower than the beta-hCG number.
- Live birth rate — a baby actually born. The number that matters to you, and the lowest of the four.
- Per cycle vs. per transfer — a cycle (one egg retrieval) can produce several embryos and several transfer attempts. "Per transfer" success looks lower than "cumulative per cycle" success, even though they describe the same retrieval.
When a clinic quotes you "70% success," always ask: 70% of what, measured how, in which age group?
Live birth rate by age (per embryo transfer)
These ranges reflect what Indian and global fertility registries report for a fresh or frozen single-embryo transfer, using the patient's own eggs:
| Age | Per transfer | Cumulative, one full retrieval |
|---|---|---|
| Under 35 | 40 – 50% | 55 – 65% |
| 35 – 37 | 30 – 40% | 45 – 55% |
| 38 – 40 | 20 – 28% | 28 – 38% |
| 41 – 42 | 10 – 15% | 12 – 20% |
| 43+ | 3 – 7% | 5 – 10% |
Donor-egg transfers sit apart from this table entirely — they run roughly 50–55% per transfer regardless of the recipient's age, because the egg's age is what drives the number, not the uterus's age. For a full breakdown of what changes practically after 35 — protocols, cycle counts, when donor eggs become the higher-odds option — see our piece on IVF after 35 in India.
Why India doesn't have one official number
In the US and UK, national registries (SART, HFEA) publish clinic-level success data every clinic must report into, which is part of why patients there can compare clinics on a like-for-like basis. India's ICMR National ART Registry collects data but doesn't yet publish it broken down by individual clinic in a way patients can browse. Until that changes, every number a clinic gives you is self-reported and unverified.
What actually moves your personal number
- Age and ovarian reserve (AMH, antral follicle count) — the single biggest factor, and the one behind the table above
- Embryo quality and genetic normalcy — rises with the number of eggs retrieved and, for some patients, with PGT-A screening
- Uterine and hormonal factors — endometrial receptivity, thyroid and prolactin levels, and structural issues your doctor screens for before transfer
- Lab and protocol quality — embryology handling, incubator technology, and whether the stimulation protocol fits your specific reserve, not a one-size-fits-all default
- Sperm quality — a meaningful factor in a significant share of cycles, independent of the woman's age
Questions to ask your clinic
- What's your live birth rate, by my age band specifically — not your overall average?
- Is that per transfer or cumulative across a full retrieval?
- How many patients is that number based on, and over what period?
- Given my AMH and AFC, what's your honest estimate for my case?
A clinic confident in its real numbers will answer all four without hesitation. See our full clinic-choosing checklist for the rest of what to evaluate beyond success rate alone, and red flags to watch for during your first visit.
The bottom line
"IVF success rate" is not one statistic — it's a family of them, and the version a clinic leads with is usually the most flattering one available. Ask for the live-birth rate, by your age band, and how it was measured. That single question tells you more than any hoarding or homepage number will.