Fertility

SART and CDC Data: What Each One Tells You

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Two national fertility datasets sit side by side, and patients often assume one must be more trustworthy than the other. In fact they draw on largely the same clinics and mostly agree. What differs is who runs each, why it exists, and how deep it lets you dig. Here is what SART and the CDC each measure, and when to reach for one over the other.

Last updated: July 2026

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What the CDC data is

The CDC data is the federal, mandatory record of IVF outcomes. The Fertility Clinic Success Rate and Certification Act of 1992 requires every fertility clinic in the United States to report its ART results, and the CDC collects and publishes them 1. The National ART Surveillance System, or NASS, is the machinery behind those numbers, defining how cycles are counted and how success measures such as live-birth delivery are constructed 2. The most recent national summary covered 457 clinics in a single reporting year 3.

Because it is required by law, the CDC dataset aims to be the complete national picture — the official baseline against which the whole field is measured. That is its defining strength: coverage and authority.

What the SART data is

The SART data is the fertility field's own registry, maintained by the professional society whose members are the clinics themselves. The Society for Assisted Reproductive Technology collects outcomes from its member clinics and publishes national figures broken out by patient age band and by cycle, with clearly defined success groupings — per intended retrieval, per new patient, per transfer, and cumulative 4.

SART's reporting is built for clinical detail. Its online tables let you slice outcomes by age and by the exact denominator, which makes it the richer tool once you know what you are looking for. Where the CDC is the ledger, SART is the working set of tables clinicians and informed patients actually read.

Why the two look almost the same

SART and the CDC nearly match because they largely measure the same cycles. Most fertility clinics in the country are SART members and also report to the CDC, so the underlying data overlaps heavily; the two are different windows onto one national body of cycles, not two independent counts 2. Small differences come from which clinics report to each and how each defines and groups its measures 4.

That overlap is reassuring. When a figure from SART and a figure from the CDC line up, it is not a coincidence — it is the same clinics counted two ways. The disagreements that remain are usually about method, not about a hidden truth one source is concealing.

Where they differ

The differences are about purpose and depth, not about which is right. A short comparison:

CDCSART
Who runs itFederal governmentThe fertility field's professional society
Why it existsLegally mandated public reportingMember registry and quality benchmarking
StrengthThe official, complete national recordDetailed age-band and per-denominator tables
FormatOnline dashboard and reportsSelectable online reports

Think of the CDC as the official national ledger and SART as the clinical workbook. They are complementary, and reading both is better than trusting either one alone.

Which one to use for what

For the official national baseline and a personalized estimate, start with the CDC. Its IVF Success Estimator turns national data into an individual projection from age, height and weight, and diagnosis for ages 20 to 50 5, which is the single most useful number for setting expectations. For a closer read of how outcomes vary by age band and denominator — the level most clinic comparisons actually need — SART's tables are stronger 4.

Learning how to read SART success rates, and knowing the CDC ART report exists as the official record, lets you cross-check a clinic's marketing against two public sources instead of taking one figure on faith. Cross-checking sart and cdc data on the same clinic is one of the simplest defenses against a cherry-picked number.

What neither dataset can tell you

Neither SART nor the CDC can tell you your own odds, and neither ranks clinics for you. Both are single-year, noncumulative national counts, not risk-adjusted report cards 2. A clinic's numbers reflect its patient population as much as its skill, so case mix and patient selection shape every figure you read. The national line is a backdrop, not a personal forecast 2.

Use the two datasets to understand the landscape and to fact-check claims — then let a clinician who knows your history translate any of it into what it means for you. The data is a starting point for questions, not a verdict.

Common questions

Neither is more accurate; they draw on largely the same clinics and mostly agree. The CDC data is the legally mandated, official national record, while SART is the fertility field's own registry with more detailed breakdowns. Small differences come from which clinics report to each and how each groups its measures — not from one being right and the other wrong.

Because they are two windows onto the same cycles. Differences arise from which clinics report to each system, how each defines and groups success measures, and their publication timing. The gaps are usually small and methodological. When a figure appears in both and they line up, that agreement is a good sign the number is solid.

SART's tables are usually better for a clinic comparison because they let you read outcomes by age band and by a matching denominator. Use the CDC as the official cross-check and for its personalized estimator. Whichever you use, compare only within your own age band and on the same denominator, and look at the multiple-birth rate too.

Reporting ART results to the CDC is required of all US fertility clinics under the 1992 law, so the CDC aims for complete coverage. SART membership is voluntary, though most clinics are members and report to it as well. That is why the two datasets overlap so heavily but are not perfectly identical.

The CDC's IVF Success Estimator is the tool designed for that. It uses national data to project an individualized live-birth estimate from your age, height and weight, and diagnosis for ages 20 to 50. It is a baseline, not a guarantee — a clinician who knows your full history can refine what it means for you.

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Cross-checking fertility data sources

  • —A clinic quoting a success figure that appears in neither the CDC's nor SART's public reports, with no data year or denominator attached.
  • —A single flattering percentage presented without an age band, when both national datasets report outcomes by age.
  • —A claim of being far above the national average with no mention of the clinic's patient population or multiple-birth rate.

This article compares two public fertility data sources; it is educational and not medical advice. How any national figure applies to your own chances is a conversation for a fertility clinician who knows your history.

References

  1. 1.Centers for Disease Control and Prevention (2024). ART Success Rates. CDC Division of Reproductive Health. linkThe Fertility Clinic Success Rate and Certification Act of 1992 requires all US fertility clinics to report ART results, which the CDC collects and publishes as the official national and clinic-level record.
  2. 2.Centers for Disease Control and Prevention (2024). NASS Technical Notes. CDC National ART Surveillance System. linkThe National ART Surveillance System defines how cycles are counted and how success measures are constructed, and its figures are single-year and noncumulative rather than risk-adjusted.
  3. 3.Centers for Disease Control and Prevention (2024). National ART Summary (2022 data dashboard). CDC Division of Reproductive Health. linkThe most recent federal national summary covered 457 clinics in a single reporting year, illustrating the CDC dataset's national coverage.
  4. 4.Society for Assisted Reproductive Technology (SART) (2024). National Summary Report (SART CORS Online). Society for Assisted Reproductive Technology. link ✓SART collects member-clinic outcomes and publishes national figures broken out by age band and by cycle, with defined success groupings (per intended retrieval, per new patient, per transfer, cumulative).
  5. 5.Centers for Disease Control and Prevention (2024). IVF Success Estimator. CDC Division of Reproductive Health. linkThe CDC IVF Success Estimator uses national data to produce an individualized live-birth estimate from age, height and weight, and diagnosis for ages 20 to 50.

5 sources, numbered by first appearance. General health information, not medical advice. AI-assisted editorial content — citations link their sources. Editorial policy

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