A data-driven analysis of U.S. maternal health outcomes using publicly available CMS hospital records, covering 206 hospitals across 38 states.
Each year, tens of thousands of women experience severe complications during childbirth — hemorrhage, organ failure, extended ICU stays, events that go far beyond a difficult delivery. CMS tracks this publicly, hospital by hospital, using clinical records that cover all delivering patients regardless of how they pay.
Of the 4,400+ hospitals in the CMS maternal health dataset, 206 had sufficient delivery volume to generate a reportable score ?CMS suppresses scores for hospitals with fewer than a minimum number of deliveries to protect patient privacy. This is not a data quality problem — it reflects the reality that most hospitals don't deliver enough babies annually to generate statistically reliable rates. — and the gap between the best and worst is stark.
The geographic variation in maternal outcomes is as striking as the hospital-level variation. Kentucky's reporting hospitals average 68 severe complications per 10,000 deliveries. Mississippi's average 579. ?State averages are the mean of individual hospital scores within that state, among hospitals with CMS-reportable data. States with only one reporting hospital should be interpreted cautiously — a single high-volume facility can shift the state average significantly. That's an 8.5× gap between two U.S. states — and the patterns don't follow the lines you'd expect. A hospital's reputation, size, or academic affiliation doesn't guarantee better outcomes.
CMS tracks C-section rates for a carefully defined patient group: first-time mothers delivering a full-term, head-down baby — the least clinically complicated deliveries. ?This group — called NTSV (Nulliparous, Term, Singleton, Vertex) — was designed specifically for apples-to-apples comparison. Removing patient complexity as a variable means variation in C-section rates is almost entirely attributable to hospital practice, not patient risk. It was designed this way deliberately — to make hospital-to-hospital comparison fair.
Among 159 hospitals with reportable scores, the average C-section rate is 23.8%. At the lowest-rate hospitals it's 16%. At the highest, 31%. The same patient, the same clinical profile — and nearly twice the likelihood of major surgery.
CMS has recognized this gap directly. Its Transforming Maternal Health (TMaH) Model, launched in 2025, explicitly targets reducing low-risk C-section rates as one of its primary aims — across 15 participating states over 10 years. ?The TMaH Model is a CMS Innovation Center program providing up to $17M in funding to participating state Medicaid agencies. It runs from 2025–2034 and includes Alabama, Arkansas, California, Illinois, Louisiana, Maine, Minnesota, Mississippi, New Jersey, Oklahoma, South Carolina, Washington D.C., Kansas, West Virginia, and Wisconsin. Source: CMS.gov/tmah
CMS tracks whether hospitals participate in a perinatal quality improvement (QI) collaborative — forums where hospitals share outcome data, benchmark against peers, and implement protocols to reduce maternal complications. ?CMS measure SM-7 is self-reported and attestation-based. Hospitals answer Yes or No — CMS does not independently verify participation. This is standard for structural measures, which track organizational commitment rather than clinical outcomes. Of hospitals providing labor and delivery services, 93.4% say they participate.
All data in this report comes from the CMS Provider Data Catalog, released as part of the Hospital Inpatient Quality Reporting (IQR) program. This is clinical data — drawn from hospital electronic health records, not insurance claims — and covers all delivering patients regardless of payer. Four measures are used: ePC-07a (risk-adjusted severe obstetric complications per 10,000 deliveries), ePC-02 (C-section rate for first-time mothers with low-risk deliveries), PC-07a/PC-02 (updated measure IDs introduced in the October 2025 release), and SM-7 (self-reported QI collaborative participation).
Complication and C-section rates are risk-adjusted by CMS methodology to account for differences in patient populations across hospitals — meaning a hospital serving higher-risk patients isn't automatically penalized. State-level figures are weighted averages of facility-level scores. Hospitals below CMS minimum volume thresholds are excluded from reported scores to protect patient privacy — this is why only 206 of 4,400+ hospitals have reportable complication scores. CMS suspended public reporting of CY 2024 results for ePC-02 and PC-07 due to known submission issues in a subset of hospitals; the most recent available period is used for each hospital where 2024 data is suppressed. SM-7 is self-reported and unverified by CMS — hospitals attest to participation without independent confirmation.