National averages, cumulative odds, what factors matter most, and how to read clinic-specific data without being misled.
The CDC publishes annual ART success rate data based on mandatory reporting from all US fertility clinics. Age of the person providing eggs is the single strongest predictor of IVF success. Here are approximate live birth rates per egg retrieval from the most recent complete data:
Egg quality declines with age due to increasing rates of chromosomal abnormalities (aneuploidy). At age 30, approximately 30% of eggs are chromosomally abnormal. By 40, that figure rises to roughly 60%, and by 44, it exceeds 90%. This is the primary driver of declining IVF success rates — not uterine receptivity or overall health, which remain relatively stable into the early 40s.
Clinics and data sources report several different metrics, and they're not interchangeable:
| Metric | What It Measures | Why It Matters |
|---|---|---|
| Live birth rate per retrieval | Percentage of egg retrievals resulting in a live birth | Most meaningful single-cycle metric — accounts for fertilization failure, no transfer, and miscarriage |
| Live birth rate per transfer | Percentage of embryo transfers resulting in a live birth | Higher number (looks better), but excludes cycles that never reached transfer |
| Clinical pregnancy rate | Percentage with confirmed heartbeat at 6–8 weeks | Inflated compared to live birth rate; doesn't account for losses after 8 weeks |
| Biochemical pregnancy rate | Percentage with positive hCG | Highest number; includes many pregnancies that don't progress |
When comparing clinics, always use live birth rate per retrieval or live birth rate per intended retrieval for the most honest comparison. Any clinic highlighting only pregnancy rates or per-transfer rates may be selectively presenting data.
Single-cycle statistics understate most patients' real chances because IVF is often a multi-cycle process. Cumulative success rates paint a much more encouraging picture:
| Age Group | 1 Cycle | 2 Cycles | 3 Cycles |
|---|---|---|---|
| Under 35 | 46% | ~68% | ~80% |
| 35–37 | 38% | ~58% | ~72% |
| 38–40 | 26% | ~42% | ~55% |
| 41–42 | 13% | ~24% | ~34% |
A landmark 2015 study in JAMA analyzing over 150,000 IVF cycles found that cumulative live birth rates after 6 cycles approached 65% even for women aged 40–42 — significantly higher than single-cycle rates suggest. The key takeaway: persistence matters, but diminishing returns beyond 3–4 cycles should be discussed with your RE.
While age dominates, several other factors meaningfully influence success:
CoQ10 (ubiquinol form, 400–600mg/day) and DHEA (for diminished ovarian reserve, 75mg/day) have clinical evidence supporting their use before IVF cycles. Always discuss supplementation with your RE before starting — timing and dosing matter.
The CDC and SART both publish clinic-level success rates, but comparing clinics requires nuance:
SART's online tool lets you filter by age group, diagnosis, and cycle type. Focus on "live births per intended egg retrieval" for your specific age group.
A clinic reporting 60% success rates for women under 35 may seem superior to one reporting 45% — but if the first clinic cherry-picks patients with good prognoses and rejects complex cases, their results aren't truly better. Ask clinics what percentage of patients they accept versus turn away.
Clinics performing fewer than 100 cycles per year have more statistical variation. A small clinic with a 55% rate could easily be average with a lucky year. Larger programs provide more reliable data.
Clinics that cancel cycles with poor response inflate their per-retrieval success rates. A clinic with a 15% cancellation rate and 50% per-retrieval success actually has a 42.5% per-intended-retrieval rate.
When using donor eggs, success rates are based on the donor's age (typically 21–32) rather than the recipient's age. This makes donor egg IVF one of the most successful fertility treatments available:
Donor egg IVF is typically recommended for women over 42, those with premature ovarian insufficiency, or patients with multiple failed cycles using their own eggs. For a complete guide to the donor egg process, see our Donor Egg IVF guide.
For women under 35, approximately 46% of first cycles result in a live birth. By age 40, that drops to about 26%. Remember these are averages — your individual factors (diagnosis, ovarian reserve, embryo quality) matter more than national statistics.
Research suggests retrieving 10–15 eggs per cycle optimizes outcomes. Fewer than 5 eggs significantly reduces the chance of having a euploid blastocyst. More than 20 eggs doesn't proportionally improve outcomes and increases OHSS risk.
Not necessarily. The first 3 cycles have relatively similar per-cycle success rates for most patients. After 3–4 failed cycles, per-cycle rates do tend to decline — suggesting the underlying issue may not be addressable by IVF. Your RE should reassess the protocol and prognosis after each failed cycle.
Yes — euploid (chromosomally normal) embryos have implantation rates of approximately 60–70% and miscarriage rates of 5–10%, compared to untested embryos which have higher miscarriage rates especially in older patients. However, PGT-A doesn't increase total live births per retrieval — it primarily reduces time to pregnancy and miscarriage risk.
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