Journal Article

Development of a quantitative job exposure matrix for standing, walking, and forward bending among pregnant workers – The PRECISE JEM

Begtrup, Luise Mølenberg, Svartengren, Magnus, Mehlum, Ingrid Sivesind, Petersen, Jonathan Aavang, Burdorf, Alex, Flachs, Esben Meulengracht, Sejbaek, Camilla Sandal, Peters, Susan, Frankel, Hannah Nørtoft, Bonde, Jens Peter, Korshøj, Mette, Hettiarachchi, Pasan, Johansson, Peter J

2025

Overview

OBJECTIVES: Occupational physical activity (OPA) during pregnancy has been linked to adverse pregnancy outcomes, but crude exposure assessment remains an issue in causal inference. We aimed to develop a quantitative trimester-specific job exposure matrix (JEM) for standing, walking, and forward bending among pregnant workers. METHODS: Accelerometer measurements from 403 female workers across 109 DISCO-08 job codes were obtained in Denmark between January 2023 and June 2024. Full workdays were measured during two weeks among pregnant workers and one week among non-pregnant workers. We used linear mixed-effects models to estimate exposure levels of occupational standing, walking, and forward bending for all 1171 DISCO-08 codes, including age, trimester, and expert ratings as fixed effects, and job codes and workers as random effects. RESULTS: The between-job variances relative to total variances were 56% for standing, 51% for walking, and 45% for forward bending. The fixed effect trimester reduced standing time by 0.38 hours during the 3rd trimester compared to non-pregnant participants, whereas no differences were observed for walking or forward bending. Based on the trimester-specific JEM for occupational standing time, bakers had the highest exposure (range from non-pregnant to 3rd trimester, 5.41–5.03 hours/workday). For walking and forward bending, the highest exposed jobs from the pregnancy-specific JEM were waiters (1.76 hours/workday) and livestock/dairy producers (1.24 hours/workday), respectively. CONCLUSIONS: The JEM enhances independent objective exposure assessment in epidemiological studies of OPA and pregnancy outcomes and may advance guidelines and potentially prevent adverse pregnancy outcomes.

• Publisher: Scandinavian Journal of Work, Environment & Health,Nordic Association of Occupational Safety and Health,Nordic Association of Occupational Safety and Health (NOROSH)
• Subject: Accelerometers / Accelerometry / Adult / adverse pregnancy outcome / Benchmarks / Codes / Denmark / Employment / Epidemiology / Exercise / Exposure / exposure assessment / Female / Female employees / forward bending / Humans / Inference / jem / job exposure matrix / linear mixed-effects model / Livestock / Livestock industry / Occupational exposure / Occupational Exposure - statistics & numerical data / occupational physical activity / Occupations / Original / Physical activity / Physical fitness / precise jem / Pregnancy / Pregnancy Trimesters / pregnant / Questionnaires / Random effects / Ratings & rankings / Self report / Speech therapy / standing / Standing Position / Walking / Workers / Working hours / Working women