Prenatal PM2.5 linked to preterm birth in Puerto Rico
In the PROTECT birth cohort, an IQR rise in pregnancy-average PM2.5 was associated with higher preterm-birth risk among relatively healthy Puerto Rican women.
Source
Preterm birth and PM<sub>2.5</sub> in Puerto Rico: evidence from the PROTECT birth cohort
Study at a glance
- Design
- Cohort — PROTECT pregnancy cohort with pregnancy-average PM2.5 and preterm-birth risk ratios
- N
- N=1092 · 1,092 PROTECT participants with live singleton births in 21 municipalities
- Population
- Pregnant women in the PROTECT cohort in Puerto Rico
- Outcome
- Preterm birth associated with prenatal PM2.5 (with phthalate-interaction tests)
Structured fields used in claim comparison tables when every cited study has a complete layer.
What they did
Authors followed 1092 PROTECT participants with live singleton births in 21 Puerto Rican municipalities (2011–2018), assigned pregnancy-average PM2.5 from nearby EPA monitors, and estimated risk ratios for preterm birth with modified Poisson models, including phthalate-interaction tests.
What they found
About 9.1% of births were preterm. Mean pregnancy PM2.5 was 6.8 μg/m³. An IQR increase in prenatal PM2.5 raised preterm-birth risk (RR 1.014 individual-adjusted; RR 1.012 also municipal-adjusted). Phthalate metabolites did not modify the association.
The limits
What it doesn't show
Monitor-based, municipality-at-birth assignment misses residential moves and fine-scale PM2.5, so exposure error likely biases toward the null; the cohort excluded major comorbidities, and few preterm births limited effect-modification power.
Key terms
- PM2.5
- Fine particulate matter with aerodynamic diameter less than 2.5 micrometers.
- Preterm birth (PTB)
- Live birth before 37 completed weeks of gestation.
- PROTECT
- Puerto Rico Testsite for Exploring Contamination Threats, a Superfund-supported prospective birth cohort.
- IQR-scaled risk ratio
- Relative risk expressed per interquartile-range change in average prenatal PM2.5.
- Modified Poisson regression
- Poisson model with robust variance used here to estimate risk ratios for a binary birth outcome.
Flashcards
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Quiz yourself
Main PROTECT finding on prenatal PM2.5:
Common questions
Did higher prenatal PM2.5 raise preterm-birth risk?
Yes—RR about 1.01 per IQR after individual and municipal adjustment.
How high was typical exposure?
Pregnancy-average PM2.5 was 6.8 μg/m³ (IQR 5.4–7.4).
Who was studied?
1092 predominantly Hispanic and Black PROTECT participants in Puerto Rico.
Did phthalates change the PM2.5 effect?
No significant interaction for DBP or DiBP metabolites.
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