Data Methodology

Primary Data Source

All data comes from the Centers for Disease Control and Prevention (CDC) via the National ART Surveillance System (NASS) at cdc.gov/art. The CDC collects this data annually from every ART (Assisted Reproductive Technology) clinic in the United States as required by the Fertility Clinic Success Rate and Certification Act of 1992. Participation is mandatory, all U.S. fertility clinics that perform ART procedures must report their cycle-level outcomes to the CDC. This makes the NASS dataset the most comprehensive and official source of fertility treatment outcome data in the country, covering every clinic regardless of whether it participates in voluntary accreditation programs. Annual Fertility Clinic Success Rates Reports and the underlying datasets are released through the CDC ART Data Portal.

Corrections

Reports of a wrong figure are checked against the source dataset before anything changes. Where a number is wrong we fix it at the point it is produced, so the corrected value reaches every page that shows it rather than being patched only where it was noticed; where a label or a claim is wrong we correct the wording, and where the wording was wrong because the underlying data model invited the mistake, we change the model too. Every material change is listed with its date on the data changelog, including corrections we have had to make more than once. To report something that looks wrong, use the contact page, or the "report a data error on this page" link at the foot of any data page, which carries the page reference with it. The full process is set out in our editorial and corrections policy.

Data Vintage and Update Frequency

PlainFertility's database spans 2020 through 2022 reporting years. The CDC releases updated NASS data annually, typically with a 1–2 year lag after the reporting period, this delay exists because the CDC must verify reported outcomes, which for ART procedures includes waiting for pregnancies to reach delivery. The 2022 data (the most recent available) covers outcomes for cycles performed during that calendar year. PlainFertility updates its database when new CDC NASS releases become available, typically in the fall following publication.

Processing Pipeline

1. Raw NASS datasets are downloaded from the CDC ART data portal, including both clinic-level summary files and national aggregate tables published alongside the annual Fertility Clinic Success Rates Report.
2. Clinic records are matched across reporting years using the persistent NASS clinic ID numbers assigned by the CDC, enabling multi-year trend analysis for individual clinics.
3. Success rates are extracted by patient age group (under 35, 35–37, 38–40, and over 40, which are the four bands the CDC publishes for own-egg cycles in this table. It reports a single bracket above age 40 rather than splitting 41–42 from 43+, so no finer breakdown exists to show), cycle type (fresh embryo transfers versus frozen embryo transfers), and outcome measure (live birth rate per intended egg retrieval or per transfer cycle).
4. Cycle volume data, including total cycles started, fresh cycles, frozen cycles, donor egg cycles, and gestational carrier cycles, is loaded for each clinic to provide context for interpreting success rates.
5. Service availability indicators are extracted for each clinic: whether the clinic offers donor egg programs and gestational carrier arrangements. (Preimplantation genetic testing and embryo banking availability are not currently part of the NASS extract PlainFertility ingests and are not shown per-clinic.)
6. State-level aggregations are pre-computed to support state summary pages showing total clinics, total cycles, and average success rates by age group.
7. All data is loaded into a structured SQLite database serving clinic profiles, state pages, search functionality, and comparison features.

How Success Rates Are Reported

PlainFertility presents CDC-reported success rates exactly as published, no adjustment, composite scoring, or proprietary ranking formula is applied. The primary success metric is live birth rate per intended egg retrieval or transfer cycle by patient age group. The CDC explicitly cautions against simplistic clinic comparisons because:

• Clinics treat patients with different diagnoses, medical histories, and prognoses, a clinic specializing in difficult cases will likely show lower raw success rates
• Clinics with more complex or older patient populations may show lower rates even with excellent clinical care and physician expertise
• Patient-specific factors including age, ovarian reserve, diagnosis (endometriosis, PCOS, male factor infertility), and treatment protocol are the strongest predictors of ART success, not the clinic itself
• Cycle type mix differs between clinics, some perform more frozen transfers (which tend to have different success profiles) than fresh transfers

Coverage

• Clinics: 495 across 51 states and territories
• Age groups: Under 35, 35–37, 38–40, Over 40
• Cycle types: Fresh embryo transfers, frozen embryo transfers, donor egg cycles
• Years: 2020, 2021, 2022
• Metrics: Live birth rate, pregnancy rate, cycle volume, and service availability

Accuracy Commitment

PlainFertility reproduces CDC NASS data exactly as published. Success rates, cycle counts, and service availability indicators are not modified, adjusted, or reweighted. When the CDC suppresses clinic-specific data due to small sample sizes, PlainFertility respects these suppressions and displays the data as unavailable rather than estimating or interpolating values. Clinic names and locations are presented as reported to the CDC.

Corpus placement (#N of M)

Clinic, state, and metro detail pages show an analytical #N of M placement inside the CDC NASS-derived PlainFertility corpus. These ranks describe relative standing in our published inventory:

• Clinics - cycle volume: national rank by total_cycles among clinics with a positive reported count (highest = #1). Tie-break: clinic slug A-Z.
• Clinics - live-birth rate: national rank by overall_success_rate among clinics with a positive reported rate (highest = #1). Tie-break: clinic slug A-Z. This is corpus placement among published rates, not a treatment recommendation or case-mix-adjusted quality score.
• States - clinic headcount: rank by clinic_count (most CDC-reporting clinics = #1). Tie-break: state abbr A-Z.
• States - cycle volume: rank by total_cycles (highest summed cycles = #1). Tie-break: state abbr A-Z. Headcount and cycle volume can diverge.
• Metros - clinic inventory: rank by clinic_count among metros with at least one reporting clinic (most clinics = #1). Tie-break: metro slug A-Z.

Corpus placement answers "where does this entity sit among the CDC-reporting clinics, states, and metros we publish?" It is not medical advice and does not replace the CDC's own age-group and cycle-type tables. Always read the success-rate methodology above and the primary CDC sources before acting.

Limitations

• Success rates reflect group averages across all patients treated at a clinic, not individual patient outcomes. Your personal success rate depends on your age, diagnosis, ovarian reserve, and treatment protocol, not the clinic's average.
• Some clinic-specific data is suppressed by the CDC when sample sizes are too small to report reliably, particularly for less common cycle types or older age groups at smaller clinics.
• Clinic rankings based on raw success rates can be misleading without controlling for patient case mix. A clinic that accepts more complex cases may appear less successful than one that selects easier cases.
• NASS data does not capture patient out-of-pocket costs, insurance coverage, or cumulative success rates across multiple cycles, only per-cycle outcomes are reported.
• PlainFertility is not affiliated with the CDC, any fertility clinic, ASRM, SART, or any healthcare organization. Do not use this data as the sole basis for choosing a fertility clinic.