Sources
The grades are the same ones we use internally. They are not a ranking of importance; they say how the number was established.
The bar for "this intervention prevents preterm birth": at least one adequately powered randomized trial, or an individual-participant meta-analysis of trials, showing a statistically significant improvement in a preterm-birth band or a neonatal morbidity or mortality outcome, in a defined population. Evidence grade A means an individual-participant meta-analysis of trials; B means a trial or a trial-based review meeting the bar with caveats stated.
| Figure | Value | Source | Grade |
|---|---|---|---|
| Births and preterm births, by state and U.S. (2023) | per state; U.S. 3,596,017 births, 373,902 preterm, 10.41% | CDC/NCHS, Births: Final Data for 2023, NVSR 74-1 (March 2025): Table 6 (births by state) and Internet Table XV (preterm births and percent, all races and origins, by state of residence, obstetric estimate). A U.S. government work; attribution only. Corrected 2026-10-29: an earlier draft of this site carried the March of Dimes 2024 Report Card's state percentages under this label; they matched the NVSR values to one decimal, and the NVSR values are used now. | validated |
| Medicaid-financed share of births, by state | U.S. ~40%; per state, 2024 | KFF State Health Facts, "Births Financed by Medicaid", 2024, KFF's compilation of CDC WONDER natality data (principal source of payment). Reproduced with citation under KFF's reuse terms (materials may be reproduced unaltered with citation where readers are not charged). One year later than the other columns. | validated |
| Average lifetime cost per preterm birth; national total | $64,815 (2016 USD); $25.2B for the 2016 cohort | Waitzman NJ, Jalali A, Grosse SD. Preterm birth lifetime costs in the United States in 2016. Semin Perinatol 2021 (PMID 33541716). Medical care $17.1B, two-thirds of the total, and over 90% of that is the inpatient stay in infancy; delivery $2.0B; early intervention and special education $1.3B; lost productivity $4.8B. By gestational age: $344,355 below 28 weeks, $28,367 at 32–36 weeks, incremental to a term birth. The authors call the estimate a floor. | validated |
| Acute NICU cost by prematurity (commercial) | ~$76k average preterm; ~$604k at 24 weeks | Beam AL et al. Estimates of healthcare spending for preterm and low-birthweight infants. J Perinatol 2020. Commercial claims; an upper anchor. | plausible |
| Medicaid preterm hospitalization cost | mean $43,858 all preterm; $222,987 below 29 weeks; $1,894 full term (2017 USD) | McLaurin KK et al. 2019, Pediatr Health Med Ther (PMC6455110). MarketScan Medicaid claims 2003–2012. | plausible |
| Prenatal care begun in the first trimester (U.S., 2023) | 76.1% | NCHS Data Brief 507, Births in the United States, 2023 | validated |
| Late or no prenatal care (U.S., 2021 → 2024) | 6.3% → 7.3%; rose in 36 states and DC | NCHS Data Brief 550, Changes in Timing of Prenatal Care Initiation, 2021–2024 | validated |
| Intervention · window | Effect | Source | Grade |
|---|---|---|---|
| Vaginal progesterone · from a short cervix at 18–24 wk, singleton with short cervix or prior spontaneous preterm birth | RR 0.78 (0.68–0.90) preterm birth <34 wk | EPPPIC Group. Evaluating Progestogens for Preventing Preterm birth International Collaborative: IPD meta-analysis of 31 trials, 11,644 women. Lancet 2021. Twins: no benefit. | A |
| Low-dose aspirin · start 12–16 wk (to 28 wk), elevated pre-eclampsia risk | OR 0.38 (0.20–0.74) preterm pre-eclampsia <37 wk | Rolnik DL et al., ASPRE trial, N Engl J Med 2017 (protocol: BMJ Open 2016). USPSTF Grade B (2021); ACOG Committee Opinion 743 on timing. Effect runs through pre-eclampsia, not spontaneous labor; APRIL (aspirin for recurrent spontaneous preterm birth) showed no clear benefit. | B |
| Cervical cerclage · before 24 wk, short cervix with prior preterm birth or mid-trimester loss | combined cerclage + progesterone vs cerclage alone RR 0.51 (0.37–0.79) <37 wk | Systematic review and meta-analysis, Am J Obstet Gynecol MFM 2023; cerclage-vs-none rests on longstanding Cochrane and IPD evidence. | B |
| Mid-pregnancy proteomic risk screen, then targeted care (PreTRM test-and-treat) · 18 wk 0 d – 20 wk 6 d, asymptomatic singletons | co-primary, intent-to-treat (n = 4,806): composite neonatal morbidity and mortality OR 0.80 (0.66–0.96, p = 0.015); neonatal hospital stay IRR 0.95 (0.92–0.98, p = 0.004); fewer NICU admissions. Grade B rests on these. The trial stopped early for benefit, and the screened arm was open-label; both tend to make an effect look larger. NICU admission 10.2% vs 12.8% (OR 0.78, 0.65–0.93), a secondary outcome; stay among those admitted did not differ. The screen-guided arm had more fetal growth restriction (5.3% vs 3.8%) and more preeclampsia at term, which the authors note without explanation. Exploratory, company-reported: −32% preterm birth <35 wk, −56% <32 wk; NICU admission −20%. Screen-positive rate 24.4% (1,226/5,018). | PRIME RCT, NCT04301518; Iriye et al. 2026, Pregnancy (Hoboken) 2(1):e70202, PMID 42597049: 19 U.S. sites, singletons at 18–20 weeks, halted for efficacy at the interim analysis; the bundle for higher-risk results was daily vaginal progesterone, low-dose aspirin and weekly nurse calls. AVERT PRETERM (Hoffman 2024, Diagnostics, doi 10.3390/diagnostics14141462): 18% reduction in severe neonatal morbidity, company-reported. Sera's earlier PREVENT-PTB trial had a null primary preterm-birth outcome. Significance of the exploratory bands is company-reported pending independent extraction. Our founder has a financial interest in wider use of this test; see About. | B exploratory bands |
| Antenatal corticosteroids · 24–34 wk when delivery expected within 7 days | reduces neonatal death, respiratory distress syndrome | McGoldrick E et al., Antenatal corticosteroids for accelerating fetal lung maturation, Cochrane Database Syst Rev 2020 (CD004454). Softens a preterm birth; does not prevent one. | A |
| Smoking-cessation support in pregnancy (psychosocial) | abstinence RR 1.44; low birthweight −17%; NICU admission −22%; preterm birth unclear | Chamberlain C et al., Cochrane 2017, 102 trials. Honest headline is birthweight and NICU, not preterm birth. Not on the timeline because it has no gestational window. | B |
| Doulas; group prenatal care (CenteringPregnancy) | no reduction in preterm birth in randomized trials | Observational doula estimates (e.g. Kozhimannil 2016, aOR 0.77) are not causal; CRADLE 2022 null on preterm birth. Credited for engagement, never for outcomes. | not credited |
| 17-OHPC (hydroxyprogesterone caproate, Makena) · formerly weekly from 16–20 wk, prior preterm birth | RR 0.83 (0.68–1.01) <34 wk; CI crosses null | EPPPIC 2021 (17-OHPC arm); PROLONG confirmatory RCT did not replicate; FDA withdrew approval April 2023. | de-adopted |
Standard-of-care windows without an effect size on this site (first-trimester visit by week 13; anatomy scan with cervical length 18–24 weeks; glucose screening 24–28 weeks; postpartum blood-pressure check within 7 days of a hypertensive pregnancy; comprehensive postpartum visit by 12 weeks; 12-month postpartum Medicaid coverage) follow ACOG practice guidance and the HEDIS prenatal and postpartum care measures. They are on the timeline because their timing is what the record is built from, not because this site claims a preterm-birth effect for them.
| Claim | Source | Grade |
|---|---|---|
| The AMA CPT Editorial Panel deleted the global obstetric package codes effective January 1, 2027. Antepartum and postpartum care are reported as individual evaluation-and-management visits (office, telemedicine, virtual check-in, home); labor management and vaginal and cesarean delivery get new codes. Imaging during pregnancy stays separately reportable, as before. In all, 17 maternity codes are deleted, 12 added and 6 revised. | American Medical Association, the AMA's CPT Editorial Panel-approved maternity care codes and guidelines, published ahead of the CPT 2027 Professional Edition. Counts are ours, from that text. The AMA notes that copyediting may make minor refinements before the codebook is final. This page states the change and reproduces no CPT descriptors, which are AMA copyright. | validated |
| Medicaid finances more than 40% of U.S. births, over half in some states. | KFF; Policy Center for Maternal Mental Health (2026). | validated |
| Unbundling risks fragmentation and administrative burden for small practices. | Policy Center for Maternal Mental Health, as above. | reported |
| Claim | Value | Source | Grade |
|---|---|---|---|
| The evidence for the cheapest steps was in place before 2019 | aspirin: USPSTF 2014 recommendation, ASPRE 2017; vaginal progesterone: trials through the 2010s, pooled by EPPPIC in 2021 | See the interventions table above. | validated |
| The 2019 financing of Sera Prognostics | $36 million Series D, announced November 2019, led by Blue Ox Healthcare Partners | Company announcement, November 2019, as carried by trade press (360Dx, FinSMEs, BioSpace). | validated |
| Preterm births, July 2019 to June 2026 | about 2.6 million; about $170 billion at $64,815 each | CDC/NCHS births and preterm rates: 2019 3,747,540 at 10.23%; 2020 3,613,647 at 10.09%; 2021 3,664,292 at 10.49%; 2022 3,667,758 at 10.38%; 2023 3,596,017 at 10.41%; 2024 3,628,934 at 10.41%; 2025 (provisional) 3,606,400 at 10.41%. Half of 2019, 2020–2025, half of 2026 at the 2025 rate. | validated (2025 provisional) |
| The company's revenue from the test, 2022–2025 (stated on the About page as the size of the founder's interest) | $268K, $306K, $77K, $81K; under $750K in total | Sera Prognostics annual and fourth-quarter results (company releases and SEC filings), which state that PreTRM revenue is substantially all of the company's revenue. "Gone public, run two randomized trials, and negotiated with payers" is from the same public releases (the 2021 IPO; PRIME and AVERT; the company's own statements on payer discussions), not from any private source. | validated |
| Low-dose aspirin reaches fewer than half of women at high risk | <50% of high-risk; <25% with more than one moderate-risk factor | Society for Maternal-Fetal Medicine special statement, Am J Obstet Gynecol 2023 (prophylactic low-dose aspirin quality metric). | validated |
| The one approved drug was withdrawn | April 2023 | FDA withdrawal of approval for hydroxyprogesterone caproate (Makena), after the PROLONG trial did not confirm benefit. | validated |
| Rural hospitals that stopped delivering babies, or said they will | 139 since the end of 2020 | Center for Healthcare Quality and Payment Reform, rural maternity care report, June 2026. Rural hospitals only; includes announced closures through 2026. | validated |
| The preterm birth rate, 2019 and 2025 | 10.23% → 10.41% | CDC/NCHS, as above. | validated |
The March of Dimes report cards are the field's shared surveillance layer and we link to them. We do not reprint their figures here; the vital-statistics record they are built from is public, and we use that directly. An earlier draft of this site did carry their state preterm percentages under an NCHS label, by mistake; the row above says how that was corrected. Nothing on this site is derived from a proprietary dataset.