Fertility Medicine
IVF Success Rates by Age: How to Read Clinic Numbers
Last reviewed: May 2026 · Haute MD Editorial Team
Age is the single biggest factor in IVF success, which is why every credible report breaks results out by the age of the person whose eggs are used. In the U.S., the two standard sources are the SART clinic reports and the CDC's national ART surveillance data. SART groups patients into age bands of under 35, 35–37, 38–40, 41–42 and over 42. Before comparing any two clinics, check four things: which age band, which denominator (per egg retrieval, per transfer or per patient), which outcome (live birth or just pregnancy) and whether donor eggs are counted separately. This guide is educational, not medical advice; your reproductive endocrinologist can tell you what the numbers mean for your diagnosis.
Where U.S. IVF success numbers come from
SART (Society for Assisted Reproductive Technology) publishes a national summary and clinic-level reports from its member clinics. This is where most clinic success-rate comparisons start. See SART.
The CDC's National ART Surveillance System collects federally required reports from U.S. fertility clinics and publishes clinic-specific and national success rates, usually with a lag of a couple of years. The CDC also offers an IVF Success Estimator for individual planning. See CDC ART Success Rates and the CDC IVF Success Estimator.
A clinic's own website may be accurate, but it can choose its best-looking metric. Always cross-check with SART or CDC data.
The four questions to ask about any success rate
Which age band? Results differ sharply between patients under 35 and over 40, so a clinic-wide average is close to meaningless.
Per what? A rate per intended egg retrieval (or per cycle started) counts everyone who began treatment. A rate per transfer only counts patients who reached transfer, so it looks higher.
Which outcome? Live birth is the outcome that matters. Positive tests and clinical pregnancies are counted before any miscarriage.
Cumulative or single transfer? Cumulative rates include frozen embryos from the same retrieval transferred later, so they are higher than a single-transfer rate.
Why two clinics with similar numbers may not be comparable
Patient mix: a clinic that treats more complex cases (diminished ovarian reserve, older patients, prior failed cycles) can post lower rates while giving excellent care.
Small numbers: in older age bands, a clinic may report only a handful of cycles, so one or two outcomes can swing the percentage.
Freeze-all and PGT practices: clinics that test embryos and transfer later may show different per-transfer and per-retrieval patterns.
Donor eggs: donor-egg cycles reflect the donor's age, not the recipient's, and are reported separately.
Reporting lag: the most recent complete reporting year is usually a couple of years old.
How to use the numbers in a consultation
1. Look up the clinic's SART report for your own age band.
2. Compare live births per intended retrieval first, then per transfer.
3. Ask how many cycles sit behind each percentage.
4. Ask about the clinic's single-embryo transfer policy and twin rate.
5. Ask what your own testing (AMH, antral follicle count, diagnosis) suggests compared with the age-band average.
Related Haute MD guides
How long does IVF take? · IVF vs. IUI · How to choose a fertility specialist in New York
Finding a fertility specialist
Start with Find a Doctor to browse Haute MD physicians by specialty and city.
Dr. Brian Levine is board-certified in reproductive endocrinology and infertility and in obstetrics and gynecology, and is Founding Partner and Practice Director of CCRM Fertility of New York.
Frequently Asked Questions
At what age does IVF success start to drop?
SART and CDC data both show success declining across the age bands, with steeper drops after the late 30s. Exact percentages change by reporting year, so check the current SART national summary rather than a number quoted secondhand.
Is "per transfer" or "per retrieval" the better number?
Per intended retrieval is the fairer starting point because it includes patients who didn't reach transfer. Per-transfer rates are useful once you have embryos.
Do donor eggs change the age picture?
Yes. With donor eggs, outcomes track the donor's age much more than the recipient's, which is why they're reported separately.
Why doesn't this page list success rates?
Rates change every reporting year and vary by clinic and patient mix. We point you to the primary sources so you see the current, correctly labeled figures.
Can I trust a clinic's website rates?
Use them as a starting point, then confirm against SART or CDC data and ask which denominator and age band they reflect.
Get Help Now
Speak with a Haute MD Fertility physician
Are you a Fertility physician?
Join Haute MD Network and have your profile featured alongside these answers.
Apply for the Network