maternal-health
Is any prenatal smoking safe for preterm birth?
Open access · cc by · source: Europe PMC
Among 25.6 million US births, even 1–2 cigarettes/day in the first or second trimester raised preterm-birth odds; quitting before pregnancy matched nonsmoker risk.
Key findings
First-trimester smoking of 1–2 up to ≥20 cigarettes/day had ORs from 1.31 to 1.53 vs nonsmokers. Low-intensity smoking in either trimester still increased risk. Quitting before pregnancy yielded risk comparable to never smokers; quitting only after conception did not fully normalize risk. Associations varied by age, race/ethnicity, and education.
Methodology
Analyzed NVSS singleton mother–infant pairs (2011–2018) with complete smoking and gestational-age data, estimating adjusted odds of preterm birth by smoking status and cigarettes/day before pregnancy and in the first/second trimester.
Limitations
Self-reported smoking on birth certificates can misclassify exposure; residual confounding and selection after excluding hypertension/diabetes limit causal claims about intervention effects.
How this study connects
Role on claims
Each row is a claim on a concept or method page where this paper supports, challenges, or qualifies the statement. Roles are hand-checked — not a model guess.
Even low-intensity maternal smoking raises preterm-birth odds; quitting before pregnancy looks like never-smoking risk.
US birth-certificate analyses showed first-trimester smoking of 1–2 to ≥20 cigarettes/day associated with ORs ~1.31–1.53 for preterm birth; low-intensity smoking in either trimester still increased risk, while quitting before pregnancy tracked with never-smoker risk.
Evidence for the claim as stated.
Active tobacco smoking maps onto many CVD subtypes, not only “heart disease” as one bucket.
Large cohort evidence linked tobacco smoking to risk across dozens of fatal and non-fatal cardiovascular disease subtypes.
Scope note — reproductive preterm endpoint ≠ adult CVD subtype incidence
Limits the claim's scope: a different population, assay, or outcome.
Maternal cigarette dose and preterm birth odds vs Conservative SHS relative-risk floors across outcomes vs Active smoking across CVD subtypes
Evidence for the claim as stated.
Open questions
Tensions this paper is part of
From concept pages' “where studies disagree.” Disagreement means the same question; scope means different assays, populations, or outcomes.
Maternal cigarette dose and preterm birth odds vs Conservative SHS relative-risk floors across outcomes vs Active smoking across CVD subtypes
Related papers in this topic
Same topic cluster — not a recommendation engine.