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Associate Professor


Department of Obstetrics and Gynecology

Department of Health Research Methods, Evidence and Impact

McMaster University
1280 Main St. West,
HSC3V - 43B
Hamilton, Ontario ​L8S 4K1
Canada



Prepregnancy body mass index in Ontario from 2012 to 2022: A population-based descriptive study


Journal article


Sahar Khademioore, Elizabeth K. Darling, Rohan DʼSouza, Giulia M. Muraca, Yanfang Guo, Laura N. Anderson
Can J Public Health, 2026


Semantic Scholar DOI PubMed
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APA   Click to copy
Khademioore, S., Darling, E. K., DʼSouza, R., Muraca, G. M., Guo, Y., & Anderson, L. N. (2026). Prepregnancy body mass index in Ontario from 2012 to 2022: A population-based descriptive study. Can J Public Health. https://doi.org/10.17269/s41997-026-01214-w


Chicago/Turabian   Click to copy
Khademioore, Sahar, Elizabeth K. Darling, Rohan DʼSouza, Giulia M. Muraca, Yanfang Guo, and Laura N. Anderson. “Prepregnancy Body Mass Index in Ontario from 2012 to 2022: A Population-Based Descriptive Study.” Can J Public Health (2026).


MLA   Click to copy
Khademioore, Sahar, et al. “Prepregnancy Body Mass Index in Ontario from 2012 to 2022: A Population-Based Descriptive Study.” Can J Public Health, 2026, doi:10.17269/s41997-026-01214-w.


BibTeX   Click to copy

@article{sahar2026a,
  title = {Prepregnancy body mass index in Ontario from 2012 to 2022: A population-based descriptive study},
  year = {2026},
  journal = {Can J Public Health},
  doi = {10.17269/s41997-026-01214-w},
  author = {Khademioore, Sahar and Darling, Elizabeth K. and DʼSouza, Rohan and Muraca, Giulia M. and Guo, Yanfang and Anderson, Laura N.}
}

Abstract

OBJECTIVES To examine temporal trends in prepregnancy body mass index (BMI) from 2012 to 2022 in Ontario, Canada, and identify disparities across sociodemographic and medical condition subgroups.

METHODS We conducted a population-based descriptive study using data from the Better Outcomes Registry & Network (BORN) Ontario. The study included 1,170,997 singleton births between April 2012 and March 2022. Prepregnancy BMI was categorized according to World Health Organization classifications. We used generalized estimating equations to assess temporal trends in mean BMI and BMI categories, with sequential adjustments for socioeconomic and medical factors. Analyses were stratified by maternal age, parity, race/ethnicity, neighbourhood income, education, and material deprivation quantiles, smoking status, and pre-existing medical conditions.

RESULTS Mean prepregnancy BMI remained stable at 25.3 kg/m2 from 2012 to 2016, then increased to 26.0 kg/m2 by 2021. From 2012 to 2022, the proportion of individuals with underweight or normal weight BMI decreased (underweight 8.6% to 6.7%; normal weight 50.2% to 46.0%), while overweight and all obesity classes increased (overweight 20.4% to 22.4%; obesity class I 13.5% to 16.2%; obesity class II 3.7% to 4.6%; obesity class III 3.6% to 4.2%). After full adjustment, average BMI increased by 0.098 kg/m2 (95% CI 0.094-0.101) annually. An inverse socioeconomic gradient was evident across neighbourhood education and income, and material deprivation quintiles, with individuals in lower quintiles exhibiting higher prepregnancy BMI compared with those in higher quintiles.

CONCLUSION Prepregnancy BMI increased significantly in Ontario between 2012 and 2022, with acceleration from 2016 onward. Marked disparities across sociodemographic subgroups highlight the need for targeted preconception health interventions.



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