A retrospective cohort study investigating the impact of maternal pre-pregnancy body mass index on paediatric health service utilization

Objective — Maternal weight during pregnancy impacts the health of both mother and baby. This project investigated associations between maternal pre-pregnancy body mass index (BMI) and the child's future health service utilization.

Methods — The study population comprised all women who delivered a singleton, live infant in Ontario between 2012 and 2014, and was assembled from data contained in the provincial birth registry. Health service utilization in the 24 months following birth was examined by linking data from the registry with other provincial health administrative databases housed at ICES.

Results — A total of 258 005 records were available for analysis. After adjusting for infant sex and maternal age, smoking status, income quintile, and pre-existing or gestational diabetes or hypertension, children born to mothers who were overweight or had obesity prior to pregnancy had increased rates of hospitalization (overweight adjusted incidence rate ratio [aIRR] 1.09, 95% confidence interval [CI] 1.06–1.12; obesity aIRR 1.20, 95% CI 1.17–1.24), physician visits (overweight aIRR 1.03, 95% CI 1.03–1.04; obesity aIRR 1.05, 95% CI 1.04–1.05) and emergency department visits (overweight aIRR 1.12, 95% CI 1.10–1.13; obesity aIRR 1.27, 95% CI 1.25–1.29) than infants born to mothers with normal pre-pregnancy BMI.

Conclusion — Excess maternal weight was associated with greater pediatric health service utilization. Rates of health service utilization appeared to increase with maternal pre-pregnancy BMI. Future study of the reasons behind this increase may allow for early education, diagnosis, and intervention in this at-risk population.