Aim: To explore the associations between acute otitis media in early childhood and prenatal and postnatal tobacco smoke exposure.
Methods: Subjects were 32 077 children born between 2000 and 2005 in the Norwegian Mother and Child Study with questionnaire data on tobacco smoke exposure and acute otitis media up to 18 months of age. Multivariate regression models were used to obtain adjusted relative risks for acute otitis media.
Results: Acute otitis media was slightly more common in children exposed to parental smoking. The incidence from 0 to 6 months was 4.7% in unexposed children and 6.0% in children exposed both prenatally and postnatally. After adjusting for postnatal exposure and covariates, the relative risk for acute otitis media 0-6 months when exposed to maternal smoking in pregnancy was 1.34, 95% confidence interval: 1.06-1.69. Maternal smoking in pregnancy was associated with acute otitis media up to 12 months of age. Compared with non-exposed children, there was a slightly increased risk of recurrent acute otitis media for children exposed both prenatally and postnatally with a relative risk of 1.24, 95% confidence interval: 1.01-1.52.
Conclusion: Even in a cohort with relatively low exposure levels of parental smoking, maternal smoking in pregnancy was associated with an increased risk of acute otitis media in early childhood.