Short-term prenatal exposure to ambient air pollution and risk of preterm birth - A population-based cohort study in Finland

Nazeeba Siddika; Aino K Rantala; Harri Antikainen; Hamudat Balogun; A Kofi Amegah; Niilo R I Ryti; Jaakko Kukkonen; Mikhail Sofiev; Maritta S Jaakkola; Jouni J K Jaakkola

doi:10.1016/j.envres.2020.109290

Short-term prenatal exposure to ambient air pollution and risk of preterm birth - A population-based cohort study in Finland

Environ Res. 2020 May:184:109290. doi: 10.1016/j.envres.2020.109290. Epub 2020 Feb 22.

Affiliations

¹ Center for Environmental and Respiratory Health Research, Faculty of Medicine, P.O. Box 5000, 90014, University of Oulu, Oulu, Finland; Medical Research Center Oulu, Oulu University Hospital, P.O. Box 8000, 90014, University of Oulu, Oulu, Finland.
² Geography Research Unit, P.O. Box 3000, 90014, University of Oulu, Oulu, Finland.
³ Public Health Research Group, Department of Biomedical Sciences, University Post Office, University of Cape Coast, Cape Coast, Ghana.
⁴ Finnish Meteorological Institute, P.O. Box 503, 00101, Helsinki, Finland.
⁵ Center for Environmental and Respiratory Health Research, Faculty of Medicine, P.O. Box 5000, 90014, University of Oulu, Oulu, Finland; Medical Research Center Oulu, Oulu University Hospital, P.O. Box 8000, 90014, University of Oulu, Oulu, Finland. Electronic address: jouni.jaakkola@oulu.fi.

PMID: 32126375
DOI: 10.1016/j.envres.2020.109290

Abstract

Background: Previous studies have provided evidence that prenatal exposure to low-level air pollution increases the risk of preterm birth (PTB), but the findings of the effects of short-term exposure have been inconclusive. Moreover, there is little knowledge on potential synergistic effects of different combinations of air pollutants.

Objectives: To assess independent and joint effects of prenatal exposure to air pollutants during the week prior to the delivery on the risk of PTB.

Methods: The study population included 2568 members of the Espoo Cohort Study, living in the City of Espoo, Finland, born between 1984 and 1990. We assessed individual-level prenatal exposure to ambient air pollutants of interest based on maternal residential addresses, while taking into account their residential mobility. We used both regional-to-city-scale dispersion modelling and land-use regression-based method to estimates the pollutant concentrations. We contrasted the risk of PTB in the highest quartile (Q₄) of exposure to the lower exposure quartiles (Q₁-Q₃) during the specific periods of pregnancy. We applied Poisson regression analysis to estimate the adjusted risk ratios (RRs) with their 95% confidence intervals (CI), adjusting for season of birth, maternal age, sex of the baby, family's socioeconomic status, maternal smoking, and exposure to environmental tobacco smoke during pregnancy, single parenthood, and exposure to other air pollutants (this in multi-pollutant models).

Results: The risk of PTB was related to exposures to PM_2.5, PM₁₀ and NO₂ during the week prior to the delivery with adjusted RRs of 1.67 (95%CI: 1.14, 2.46), 1.60 (95% CI: 1.09, 2.34) and 1.65 (95% CI: 1.14, 2.37), from three-pollutant models respectively. There were no significant joint effects for these different air pollutants (during the week prior to the delivery).

Conclusion: Our results provide evidence that exposure to fairly low-level air pollution may trigger PTB, but synergistic effects of different pollutants are not likely.

Keywords: Air pollution; Fine particulates; Nitrogen dioxide; Prenatal exposure; Preterm birth.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants* / adverse effects
Air Pollutants* / analysis
Air Pollution* / adverse effects
Cohort Studies
Female
Finland / epidemiology
Humans
Infant, Newborn
Maternal Exposure / adverse effects
Particulate Matter / adverse effects
Pregnancy
Premature Birth* / chemically induced
Premature Birth* / epidemiology
Prenatal Exposure Delayed Effects* / chemically induced
Prenatal Exposure Delayed Effects* / epidemiology

Substances

Air Pollutants
Particulate Matter