Journal of Epidemiology
Online ISSN : 1349-9092
Print ISSN : 0917-5040
ISSN-L : 0917-5040

This article has now been updated. Please use the final version.

Tobacco Exposure During Pregnancy and Infections in Infants up to 1 Year of Age: The Japan Environment and Children’s Study
Koichi HashimotoHajime MaedaHajime IwasaHyo KyozukaRyo MaedaYohei KumeTakashi OnoMina ChishikiAkiko SatoYuka OgataTsuyoshi MurataKeiya FujimoriKosei ShinokiHidekazu NishigoriSeiji YasumuraMitsuaki Hosoyathe Japan Environment and Children’s Study (JECS) Group
Author information
JOURNAL OPEN ACCESS Advance online publication
Supplementary material

Article ID: JE20210405

version.2: August 10, 2022
version.1: April 09, 2022

Background: Tobacco exposure during pregnancy is associated with several adverse outcomes in infants. We investigated the association between tobacco exposure during pregnancy (both active and second-hand) and various infections in infants up to 1 year.

Methods: This prospective cohort study used a fixed dataset (jecs-an-20180131) from the Japan Environment and Children’s Study of registered births in Japan during 2011–2014 that included 104,065 fetal records from enrolled pregnant women. Based on the participants’ responses to the questionnaire on smoking status, mothers were first divided into “never smoked,” “quit smoking,” and “current smoker” groups and then into “no second-hand smoking (SHS)” and “SHS” groups. Infectious diseases included central nervous system infection, otitis media (OM), upper respiratory tract infection (URTI), lower respiratory tract infection (LRTI), gastroenteritis (GI), and urinary tract infection. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated using logistic regression analysis and adjusted for maternal, socioeconomic, and postnatal confounding factors.

Results: Among the 73,205 newborns enrolled, multivariable analysis revealed that the aOR of LRTI and GI was 1.20 (95% CI, 1.07–1.33) and 1.18 (95% CI, 1.04–1.35), respectively, for the “current smoker with/without SHS” group compared with the “never smoked without SHS” group. “Quit smoking without SHS” was not associated with the risk of LRTI. SHS was associated with an increased risk of OM, URTI, LRTI, and GI, especially with LRTI and GI.

Conclusion: Exposure to tobacco smoke during pregnancy was associated with an increased risk of OM, URTI, LRTI, and GI in infants during their first year of life.

Content from these authors
© 2022 Koichi Hashimoto et al.

This is an open access article distributed under the terms of Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.