IVF Success Rates Explained
CDC-reported live birth rates by age, procedure type, and clinic. Find out what to realistically expect — and how to read the numbers clinics publish.
Understanding IVF Success Rate Numbers
Every fertility clinic in the United States that performs IVF is legally required to report outcome data to the CDC each year under the Fertility Clinic Success Rate and Certification Act of 1992. The CDC then publishes this data in the annual ART (Assisted Reproductive Technology) Surveillance Report, typically 18 months after the reporting year. This makes CDC data the most objective, standardized comparison available.
The primary metric the CDC tracks is live birth rate per intended egg retrieval. This counts every cycle that began with the goal of retrieving eggs — including cycles that were cancelled due to poor ovarian response, cycles where fertilization failed, and cycles where the embryo did not survive to transfer. Because nothing is excluded, this is the least gameable of the available metrics.
Some clinics publish "pregnancy rate" instead of live birth rate. A clinical pregnancy — defined as a fetal heartbeat seen on ultrasound — sounds reassuring, but it includes pregnancies that later end in miscarriage or stillbirth. The gap between pregnancy rate and live birth rate is real and clinically meaningful: for patients over 40, miscarriage rates can exceed 50%. Live birth rate is the only metric that reflects the outcome you are actually paying for.
You will also see per-cycle and cumulative rates published side by side. A per-cycle rate is the probability of success in a single egg retrieval attempt. A cumulative rate is the probability of achieving a live birth across multiple cycles (typically 3 or 6). Cumulative rates are mathematically higher and are calculated using the formula 1 − (1 − rate)³ for three cycles. Both are legitimate, but they must be clearly labeled — cumulative rates presented without that label are misleading.
Age is the dominant variable in all of this data, which is why CDC rates are always broken down by five age bands: under 35, 35–37, 38–40, 41–42, and over 42. Comparing a clinic's overall rate to another clinic's overall rate without accounting for patient age mix is meaningless. A clinic that predominantly treats younger patients will always show higher aggregate rates than a clinic specializing in complex or older patients — even if the second clinic delivers better care.
Finally, volume matters. The CDC flags clinics that performed fewer than 20 cycles in a given category and suppresses rates for those groups because the sample size is too small for statistical reliability. A 60% success rate based on 5 cycles is essentially noise. Look for clinics with 20+ cycles in your age group before drawing any conclusions.
National Average Live Birth Rates by Age
CDC 2022 ART Surveillance Report — live birth rate per intended egg retrieval
| Procedure | Under 35 | 35–37 | 38–40 | 41–42 | Over 42 |
|---|---|---|---|---|---|
Fresh IVF — own eggs Most commonly compared metric | 51.4% | 37.2% | 22.6% | 11% | 4.5% |
Frozen embryo transfer — own eggs Often higher than fresh for some age groups | 47.8% | 38.1% | 27.4% | 14.2% | 6.1% |
Fresh IVF — donor eggs Rates reflect recipient age, not donor age | 53.2% | 51.8% | 50.1% | 48.6% | 46.9% |
Frozen embryo transfer — donor eggs Most common path for patients 43+ | 49.4% | 48.2% | 46.8% | 45% | 43.1% |
Source: CDC 2022 ART Surveillance Report, published 2024. All figures are live birth rate per intended egg retrieval for the US as a whole. Individual clinic rates vary substantially.
What Affects IVF Success Rates
Age
Age is the single strongest predictor of IVF success. Egg quality and quantity decline significantly after 35, and fall sharply after 40. This is why CDC data is always broken down by age group — comparing rates without accounting for age is meaningless.
Diagnosis
The underlying reason for infertility matters. Tubal factor, ovulatory dysfunction, and unexplained infertility generally respond better to IVF than severe male factor or diminished ovarian reserve. Your reproductive endocrinologist can estimate your prognosis based on your specific diagnosis.
Clinic Lab Quality
Embryology lab conditions — temperature, air quality, incubator type, and embryologist experience — directly affect fertilization and blastocyst development rates. An identical patient with identical eggs can get different outcomes at different labs. Volume matters: high-volume labs maintain tighter quality control.
Protocol
Stimulation protocols, trigger timing, embryo selection criteria, and whether fresh or frozen transfer is used all influence outcomes. Leading clinics continuously audit and refine protocols. Ask your physician about their approach to poor responders or patients with your specific diagnosis.
Red Flags When Reading Clinic Stats
- Quoting "pregnancy rates" instead of CDC-reported live birth rates — a positive test is not a baby
- Publishing cumulative success rates (3 or 6 cycles) without clearly labeling them as cumulative
- Reporting rates only for patients who reached transfer — this excludes cancelled cycles
- No CDC/SART data link on their website, or data that is more than 3 years old
- Very high rates with unusually low cycle volumes — statistically unreliable with fewer than 20 cycles
- Refusing to share their clinic-specific CDC report or redirecting to marketing testimonials
- Rates for "our best patients" or "optimal candidates" without defining those criteria
The CDC ART report for any clinic is publicly available at cdc.gov/art. If a clinic is hesitant to share or discuss their CDC data directly, that hesitancy itself is informative.
Frequently Asked Questions
What is a good IVF success rate?
For patients under 35 using their own eggs, a live birth rate above 50% per cycle is considered strong — the CDC national average is 51.4% for this group. Success rates decline significantly with age: 37.2% for ages 35–37, 22.6% for 38–40, and 11% for 41–42. Rather than searching for the highest number, focus on clinics with rates at or above the national average for your age group that also report adequate cycle volumes (20+ cycles).
How are IVF success rates calculated?
The CDC measures IVF success as live birth rate per intended egg retrieval — the number of cycles that resulted in a live birth divided by the total number of egg retrievals attempted, including cycles that were cancelled before transfer. This is the least gameable metric because it does not allow clinics to exclude cancelled or failed cycles. Clinics are required by law to report this data to the CDC every year.
Why do success rates vary so much between clinics?
Success rates vary for several reasons: patient mix (a clinic treating older or more complex patients will show lower rates even if it delivers excellent care), lab quality (embryology lab conditions and embryologist expertise differ substantially), stimulation protocols, and case selection. Some clinics achieve higher rates partly by declining to treat patients with poor prognosis. Always compare clinic rates to the national average for your specific age group, not to other clinics in isolation.
Should I choose the clinic with the highest success rate?
Not necessarily. The highest published rate may reflect patient selection rather than clinical excellence. Prioritize clinics with rates at or above the national average for your age group, a volume of 20+ cycles in your category (ensuring statistical reliability), and transparent reporting practices. Proximity, cost, physician communication style, and experience with your specific diagnosis also matter enormously.
What is the difference between pregnancy rate and live birth rate?
Pregnancy rate (also called clinical pregnancy rate) measures cycles that result in a positive pregnancy test or fetal heartbeat. Live birth rate measures cycles that result in a baby born alive. The gap between these two numbers reflects pregnancy losses after a positive test. The CDC prioritizes live birth rate because it is the outcome patients actually care about — a pregnancy that ends in miscarriage is not a successful treatment. Always use live birth rate when comparing clinics.