Contraintes psychosociales au travail et symptômes dépressifs majeurs chez les femmes enceintes

The goal of our thesis was to evaluate psychosocial work demands and major depressive symptoms among pregnant women. More specifically, we evaluated factors associated with major depressive symptoms, "high-strain" or "Iso-strain" jobs, and measure the association between those psychosocial work demands and major depressive symptoms among pregnant workers.  Data analyzed are from the Montreal Prematurity Study, a prospective cohort study conducted in Montréal from May 1999 to April 2004. The study looked at prematurity among 5337 pregnant women recruited at 24-26 weeks of pregnancy in four hospitals in Montréal (Québec, Canada). The CES-D scale (Center for Epidemiological Studies Depression Scale) was used to measure major depressive symptoms (CES-D score ≥23). Karasek's abbreviated scale was used to measure psychosocial work demands.  Four scientific articles have been written about the current study and will be submitted to peer-reviewed journals.  The objectives of the first article were to compare the prevalence of major depressive symptoms between subgroups of pregnant women: working women, women who had stopped working, housewives and students; and to identify risk factors for major depressive symptoms during pregnancy. At 24-26 weeks of pregnancy, prevalence of major depressive symptoms was 11.9% (11.0–12.8%) for all pregnant women (N=5 337). Working women had lower rates of major depressive symptoms [7,6% (6,6-8,7%); n=2 514] than housewives, for whom prevalence was highest [19,1% (16,5-21,8%); n=893], followed by women who had stopped working [14,4% (12,7-16,1%); n=1 665] and students [14,3% (10,3-19,1%); n=265]. Personal characteristics (non-occupational) associated with major depressive symptoms were, after adjusting for all variables, employment status, low level of education, low social support outside of work, having experienced acute stressful events, lack of money for basic needs, experiencing marital strain, chronic health problem, country of birth, and smoking.   The objective of the second article was to describe the exposure to psychosocial work demands and to identify factors that are associated among pregnant women in Montréal, Québec (N=3 765). In total, 24.4% of pregnant women were exposed to "high-strain" jobs and the proportion of workers exposed to "Iso-strain" was 69.1%. Risk factors associated with "high-strain" jobs were as follows: low social support at work, some sector of activity and skill level, working over 35 hours a week, irregular schedules, posture at work, lifting loads, young age of mothers, immigration ≥ 5 years, low level of education, single parenthood, and annual household income <$50,000.  The third article evaluated the association between psychosocial work demands and major depressive symptoms among working pregnant women (N=3 765). In bivariate and multivariate analyses, pregnant women who had "high-strain" or "Iso-strain" jobs were more likely to have major depressive symptoms. Psychosocial work demands were associated with the mental health of pregnant women, when other organizational and personal factors which they encountered outside the work settings were taken into account. Our study confirms accumulated findings related to Karasek and Theorell's "demand-control" and "demand-control-support" theoretical models. The impact of the "demand-control-support" model and the critical role of social support at work have been demonstrated among working pregnant women. The "buffer" hypothesis of "demand-control-support" model was refuted.   The objectives of the fourth article were as follows: assess exposure to psychosocial work demands among working pregnant women and women on preventive withdrawal from work; and measure the association between psychosocial work demands and major depressive symptoms, according to time of withdrawal from work (N=3 043). At 24-26 weeks of pregnancy, women on preventive withdrawal from work (31.4%) had been more exposed to "high-strain" jobs (31.1% vs. 21.1%) and "Iso-strain" (21.0% vs. 14.2%) than those who continued to work (p<0.0001), and had higher proportions of major depressive symptoms. After adjustment for personal and professional risk factors, "Iso-strain" remained significantly associated with major depressive symptoms in working women and women on preventive withdrawal from work, regardless of duration of activity before withdrawal (4 to 12 weeks/ 13 to 20 weeks/ ≥21 weeks).   Psychosocial work demands are an important risk factor for the mental health of pregnant workers. Despite the application of preventive measures during pregnancy, screening and intervention measures should be implemented in workplaces to reduce the prevalence of prenatal mental health problems and exposure to psychosocial work demands so as to prevent maternal and neonatal complications. In addition, prenatal depression is the main risk factor for postpartum depression, and infants born of mothers who suffer from depression are at higher risk of prematurity and low birth weight.

Keyphrases: Contraintes psychosociales au travail ("high-strain" job, "Iso-strain"), Pregnant women at work, Major depressive symptoms (CES-D scale), Psychosocial work demands (Job strain, Iso-strain), Working conditions, Preventive withdrawal from work