Maternal smoking in pregnancy and child's hospital use up to 5 years of age in a data linkage birth cohort

Objectives: To examine if exposure to maternal smoking during pregnancy is associated with emergency department (ED) presentation and admission through the ED in children up to 5 years after birth.

Methods: Antenatal records of all children up to 5 years of age who were born in Tasmania, Australia, between July 2008 and June 2014 were linked to health service use (ED presentations and hospital admissions). Negative binomial regression was used to estimate the incidence rate ratio (IRR) and 95% confidence intervals (CIs) at ≤1 year and ≤5 years for ED presentations and admissions to the hospital through the ED for any reason and by 9 major disease categories for children exposed versus children not exposed to maternal smoking during pregnancy. Models were adjusted for sex, socioeconomic position, maternal age at birth, and region of residence. Presentations and admissions for poisoning and injuries were used as a negative control.

Results: Among 36 630 infants, 21% were exposed to maternal smoking during pregnancy. Exposed children had a 26% higher rate of presentation to the ED (IRR_adjusted 1.26; 95% CI 1.23-1.29) and a 45% higher rate of admission (IRR_adjusted 1.45; 95% CI 1.39-1.51) at up to 5 years of age. Compared with the negative control, higher presentation and admission rates were evident in respiratory; eyes, ears, nose, and throat; psychosocial; and infectious disease categories.

Conclusions: Higher health care service use was observed in children exposed to maternal smoking during pregnancy for a range of conditions associated with exposure to smoking. The findings reinforce the need to reduce smoking among people in their childbearing years.