Population-based study on occupational risk factors for preeclampsia and gestational hypertension

Preeclampsia is a leading cause of maternal and perinatal morbidity. Work-related factors may influence the occurrence of this disorder. This case-control study estimated the associations between work-related physical and psychosocial factors and the risk of preeclampsia and gestational hypertension.

The eligible women consisted of a random sample of the women who delivered a singleton live birth in 1997-1999 in six regions of Quebec and worked during pregnancy. Cases of preeclampsia (N=102) and gestational hypertension (N=99) were compared with normotensive controls (N=4381). Information on occupational exposures at the onset of pregnancy was collected during phone interviews a few weeks after delivery. Detailed information was obtained on work schedule, postures, physical exertion, work organization, noise, vibration, and extreme temperature. Adjusted odds ratios (aOR) were estimated through polytomous logistic regression.

Women standing daily at least 1 hour consecutively without walking experienced a higher risk of preeclampsia [aOR 2.5, 95% confidence interval (95% CI) 1.4-4.6], as well as women climbing stairs frequently (aOR 2.3, 95% CI 1.2-4.1) and women working more than 5 consecutive days without a day-off (aOR 3.0, 95% CI 1.0-9.5). Squatting or kneeling, pushing or pulling objects, whole-body vibration, forced pace, job strain, and no control on breaks were positively, but nonsignificantly, associated with preeclampsia. The associations were weaker for gestational hypertension.

These findings suggest that being exposed to physically demanding and stressful occupational conditions at the onset of pregnancy increases the risk of preeclampsia.