<p>Objectives To explore the association between working conditions during first trimester and total preterm birth (PTB), and subtypes: spontaneous PTB and iatrogenic PTB, additionally to explore the role of hypertension. Methods Pregnant women from the Amsterdam Born Children and their Development study, filled out a questionnaire between January 2003 and March 2004, two weeks after first prenatal screening (singleton liveborn, n=7561). Working conditions were working hours/week, standing/walking hours/week, physical work load and job strain. Results Prolonged standing/walking during first trimester was associated with an increased risk for total PTB (OR=1.5; 95% CI 1.0-2.3, after adjustments). Other working conditions were not related to total PTB. The separation into spontaneous and iatrogenic PTB revealed that standing/walking was associated with iatrogenic PTB only (OR=2.09; 95% CI 1.00-4.97). The highest risk was found for the combination of a long workweek with high physical work load (OR=3.42; 95% CI 1.04-8.21). Hypertension did not mediate these associations; however, stratified analysis revealed that high physical work load was only related to iatrogenic PTB when pregnancy-induced hypertension was present (OR=6.44; 95% CI 1.21-29.76). Conclusion This study provides evidence that high physically demanding work is associated with an increased risk for iatrogenic PTB and not with spontaneous PTB. Pregnancy-induced hypertension may play a role: when present, high physical work load leads to a more severe outcome.</p>

doi.org/10.1136/oemed-2020-107072, hdl.handle.net/1765/136486
Occupational and Environmental Medicine
Erasmus MC: University Medical Center Rotterdam

Dr. Tanja Vrijkotte, T (Teus) Brand, & GJ (Gouke) Bonsel. (2021). First trimester employment, working conditions and preterm birth. Occupational and Environmental Medicine, 78(9), 654–660. doi:10.1136/oemed-2020-107072