IVF Success Rates by Age: The Core Data
This data comes from the CDC's National ART Surveillance System and SART (Society for Assisted Reproductive Technology), which track outcomes from nearly every fertility clinic in the United States. These are live birth rates per embryo transfer—the metric that actually matters.
A few things jump out immediately. First, the drop-off between 37 and 40 is steep—this is when egg quality and chromosomal normalcy decline most rapidly. Second, donor eggs essentially "reset" the age clock, maintaining high success rates regardless of the recipient's age. This is one of the most powerful data points in reproductive medicine.
| Age Group | Live Birth / Transfer | Live Birth / Cycle Started | Miscarriage Rate | Avg Eggs Retrieved |
|---|---|---|---|---|
| Under 35 | 50–55% | 40–45% | 10–15% | 15–20 |
| 35–37 | 30–40% | 25–33% | 15–20% | 10–15 |
| 38–40 | 20–25% | 15–20% | 25–30% | 7–12 |
| 41–42 | 10–15% | 8–12% | 35–40% | 4–8 |
| Over 42 | 3–5% | 2–4% | 45–50% | 2–5 |
| Donor Eggs | 45–55% | 40–50% | 10–12% | Varies by donor |
Understanding the Metrics: What Clinics Actually Mean
When a clinic says "our success rate is 60%," your first question should be: 60% of what? The same clinic can quote wildly different numbers depending on which metric they use.
The Metrics, Ranked by Usefulness
1. Live birth rate per embryo transfer — This is the gold standard. It tells you: of embryos that were transferred, how many resulted in a baby being born. This is the number that matters to you as a patient.
2. Live birth rate per cycle started — Slightly lower than per-transfer rates because some cycles get canceled before transfer (poor response, no viable embryos). More conservative and arguably more honest.
3. Clinical pregnancy rate — A positive pregnancy confirmed by ultrasound. Sounds great, but doesn't account for miscarriage. Typically 5–15% higher than live birth rates.
4. Chemical pregnancy rate / "positive test rate" — The most inflated metric. Counts any positive hCG, including pregnancies that end within weeks. If a clinic leads with this number, be skeptical.
Ask your clinic: "What is your live birth rate per embryo transfer for my age group, using own eggs?" If they hesitate, redirect to a different metric, or can't break it down by age, that tells you something. Every reputable clinic tracks and reports this data to SART.
Cumulative Success: The Story Gets Better With Time
Single-cycle success rates can feel discouraging, especially for patients over 37. But the cumulative picture—your total chance of success across multiple cycles—tells a much more complete story.
| Cycles Completed | Under 35 | 35–37 | 38–40 | 41–42 |
|---|---|---|---|---|
| After 1 cycle | 50–55% | 30–40% | 20–25% | 10–15% |
| After 2 cycles | 70–75% | 50–60% | 35–45% | 20–28% |
| After 3 cycles | 80–85% | 65–75% | 45–55% | 28–35% |
| After 4+ cycles | 85–90% | 75–82% | 50–60% | 32–40% |
Look at those numbers. For women under 35, the cumulative success rate after three cycles approaches 85%. Even for women 38–40, three cycles gives you roughly a coin-flip chance. These aren't lottery odds—they're workable probabilities. The challenge, of course, is that each cycle costs $20,000+ and takes 4–6 weeks. This is where financial planning and cost optimization become critical.
Most reproductive endocrinologists consider 3 complete IVF cycles a reasonable trial before reassessing the overall treatment approach. If three well-executed cycles with good-quality embryos haven't resulted in a pregnancy, it's worth exploring additional factors like uterine receptivity, immunological issues, or moving to donor eggs. This isn't giving up—it's adapting your strategy based on data.
What Actually Affects Your IVF Success Rate
Age is the headline factor, but it's not the whole story. Here's what else moves the needle:
Factors You Can't Change (But Should Know About)
- Egg quality (driven by age) — The primary reason success rates decline. Eggs accumulate chromosomal errors over time. A 25-year-old's eggs have roughly a 75% euploid (chromosomally normal) rate; by 40, it's approximately 30%.
- Ovarian reserve (AMH and antral follicle count) — Low reserve means fewer eggs retrieved per cycle, which means fewer embryos to work with. Doesn't necessarily mean lower quality per egg, but the math is harder.
- Diagnosis — Tubal factor and male factor infertility often have excellent IVF prognoses because the underlying gametes may be healthy. Endometriosis and diminished ovarian reserve tend to have more variable outcomes.
- Previous pregnancy history — Having had a prior pregnancy (even ending in loss) is generally a positive prognostic indicator for IVF.
Factors You Can Influence
- Lifestyle optimization — BMI between 19–30, not smoking, moderate alcohol consumption, and regular exercise are all associated with better IVF outcomes in the research.
- Supplement protocol — CoQ10, DHEA (for diminished ovarian reserve, under supervision), vitamin D, and a quality prenatal started 3 months before treatment have evidence supporting improved outcomes.
- Clinic selection — Lab quality and embryologist experience matter enormously. The difference between a good lab and a great lab can be 10–15% in success rates.
- Protocol optimization — Working with an RE who adjusts your stimulation protocol based on your individual response (rather than using a one-size-fits-all approach) improves outcomes.
- PGT-A testing — For patients over 37, testing embryos for chromosomal normalcy before transfer can increase per-transfer success rates and reduce miscarriage risk. It doesn't create better embryos, but it prevents transferring ones that wouldn't have worked.
How to Compare Clinic Success Rates (Without Getting Fooled)
Clinic success rates are publicly available through SART and the CDC IVF Success Estimator. These are powerful tools—but they require context.
Why High Success Rates Don't Always Mean Better Care
Some clinics achieve impressive-looking numbers by being selective about who they treat. They might decline patients with low ovarian reserve, recommend donor eggs earlier, or cancel cycles before retrieval if the response isn't ideal. Their reported success rates look fantastic, but that's partly because they've filtered out the harder cases.
Other clinics take on everyone—including patients with diminished ovarian reserve, older patients using their own eggs, and patients who've failed at other clinics. Their success rates may look lower on paper, but they're treating a genuinely harder patient population.
Instead of just comparing headline success rates, look at: (1) success rates for your specific age group, (2) the number of cycles the clinic performs annually (higher volume generally correlates with better lab quality), (3) their single embryo transfer rate (higher is better—it means they're confident in their lab), and (4) patient reviews about communication, wait times, and how the clinic handles failed cycles. A clinic that's great at getting you pregnant but terrible at communicating makes an already stressful process worse.
Donor Eggs: A Different Equation
Using donor eggs fundamentally changes the success rate math. Because the eggs come from a young, screened donor (typically in their 20s), the recipient's age barely affects outcomes. This is a genuine game-changer for patients over 40.
| Own Eggs (age 42) | Donor Eggs (any age) | |
|---|---|---|
| Live birth per transfer | 10–15% | 45–55% |
| Miscarriage rate | 35–40% | 10–12% |
| Chromosomal normalcy | ~25% | ~70% |
| Average cycles to baby | 4–6+ | 1–2 |
| Cost per attempt | $20,000–$25,000 | $30,000–$50,000 |
Donor eggs cost more per cycle but often cost less total because fewer cycles are needed. For a 42-year-old who might need 4–6+ cycles with own eggs ($80K–$150K+) versus 1–2 cycles with donor eggs ($30K–$60K), the math speaks for itself. This isn't about giving up on your genetics—it's about choosing the path with the best odds for your family.
How to Improve Your Individual Odds
You can't change your age or your ovarian reserve. But there are evidence-backed steps that can move your success rate in the right direction:
- Start a supplement protocol 3 months before IVF. CoQ10 (200–600mg daily) is the most well-studied supplement for egg quality. Add a quality prenatal with methylated folate, vitamin D (if deficient), and discuss DHEA with your RE if you have diminished ovarian reserve.
- Optimize your weight if needed. BMI between 19–30 is associated with the best IVF outcomes. Both underweight and significantly overweight can reduce success rates and increase complications.
- Stop smoking. Smoking accelerates egg aging by approximately 10 years. If you smoke, quitting 3+ months before IVF is one of the single most impactful changes you can make.
- Consider PGT-A if you're 37+. Testing embryos before transfer doesn't improve overall take-home baby rates per retrieval, but it does improve per-transfer success rates and reduces the emotional toll of transferring embryos that were never going to work.
- Choose your clinic based on lab quality. Ask about blastocyst formation rates, embryologist experience, and whether the lab has achieved specific accreditations. A great lab can be the difference between 0 and 3 viable embryos.
- Advocate for protocol adjustments. If your first cycle didn't go well, your RE should modify the stimulation protocol. Same inputs, same outputs. Push for changes.