The aim of this study was to investigate the prospective influence of work-related factors on symptoms of PPD, i.e., whether precarious working conditions, WPC, and ERI ratio increase the risk for PPD. In this prospective cohort study precarious working conditions, WPC, and ERI ratio were each significantly positively associated with symptoms of PPD within regression models, when controlling for age, professional education, parity, and anxiety during pregnancy. Within a regression including all three predictors, i.e., precarious working conditions, WPC, and the ERI reward scale), all predictors remained significantly associated with PPD. Therefore, precarious working conditions and WPC might act as prospective risk factors for PPD, whereas reward at work might act as a protective factor.
Precarious working conditions
Precarious working conditions such as defenselessness to authoritarian treatment (subscale vulnerability), low or insufficient wages, less social security benefits, less workplace rights, and powerlessness to exercise those rights might act as prospective risk factors of PPD. The effects seem to spill over into the postpartum period of maternity leave. In this study, the subscale wages showed the strongest association with symptoms of PPD within participants with higher education. The association of wages with symptoms of PPD was surprising as a recent meta-analysis found no association between education or income as a risk factor for PPD (62). A higher association with vulnerability was expected since its previously found strong relationship with mental health (16).
Work-privacy conflict and effort-reward imbalance
A perceived interference from work into private life might and also a perceived imbalance between effort put into and reward achieved from work act as a prospective risk factor for symptoms of PPD. The effects seem to spill over into the postpartum period. In another study comparing the measures of WPC and ERI, the association between effort-reward imbalance and PPD was not stronger than the association between WPC and PPD. Among hospital employees in Switzerland, both concepts were found to be significantly associated with burnout, but WPC was found to be a stronger predictor for burnout than the ERI among health professionals (63). Interestingly, when looking at groups of hospital staff with different levels of professional education, the ERI ratio has been found to be more relevant for burnout in tertiary-educated staff than WPC. This indicates that in higher educated, professional groups such as therapists, physicians, and medical-technical staff, WPC seems less important than an effort-reward imbalance for mental health (63). This could be due to a different perspective on the job such as higher personal commitment and will to work after hours. In contrast, higher educated professionals generally show a higher ERI ratio (51) and therefore might be particularly susceptible to burnout or other negative health outcomes. Hence, future analysis should classify between different kinds of professional groups within the peripartum population to investigate different influences of WPC and ERI on PPD. Moreover, among employees in a hospital setting, Hämmig (36) could show that exposure to stress and the outcomes burnout and intention to leave the profession were partly or largely mediated by WPC and ERI in physicians. Whereas WPC predicted burnout symptoms, the ERI ratio most strongly predicted thoughts of leaving the profession, indicating that WPC and ERI measure different aspects of psychosocial work stress and therefore might predict different outcomes (36). More research is needed to draw better conclusions.
While the ERI ratio did not remain a significant predictor of PPD in a regression with WPC and precarious working conditions (see Table 4), the ERI subscale reward did proof to be a significant predictor of PPD. The reward subscale had a stronger association with the outcome in the peripartum period. This has also been found in another study, where reward, rather than effort, was found to be positively associated with gestational age (38). Recent findings indicate that ERI scores can fluctuate during the prepartum period (39, 40). The factor scores for effort and reward seem to decline during the course of pregnancy, which means that women put less effort into work but also receive less reward from it. Siegrist & Li (33) also conclude that aspects of low reward at work seem to be particularly important for biomarkers and therefore physical correlates of health. Reward at work therefore might be especially important for expectant mothers and should thus be investigated to a greater extent. It further needs to be noted that a steady ERI ratio was not shown for all participants in those previous studies (39, 40). Therefore, it seems important to consider individual or systematic differences in the trajectory of the ERI.
Strenghts and limitations
This study is the first one to include multiple theoretical approaches of work stress within a representative sample of women in the peripartum period. In addition, no studies were found that applied the WPC and the EPRES to the peripartum period. The investigation is part of a large prospective-longitudinal cohort study covering many fields of interest regarding employment, mental health, and associated factors (42). Therefore, it will be possible to incorporate more theoretical concepts and factors in future analyses. Examples include paternal mental health as well as hair cortisol levels of fathers, mothers, and their offspring as biological indicators of stress within the DREAM-study. It is the aim to further investigate the impact of work-related factors on the well-being of all family members.
However, some possible limitations need to be noted. The applications of findings in this study to the general population might be limited because the sample is highly educated in comparison to the general female population of Dresden. However, previous research has shown that self-selection according to sociodemographic variables such as education had little impact on prevalence estimates (64). Concerning the predictors, the ERI ratio itself might be modified by the peripartum period with changing perspectives on work (40). Changes of the ERI score could not be observed due the lack of assessment before the pregnancy. Within the EPRES, the scale rights, concerning workplace rights, showed a low internal consistency unlike described by the authors (16, 17). This could be due to the used answer categories: “yes”, “no”, “don’t know”: Most of the participants in this study were in an employment situation with the workplace right “paid maternity leave”, but most did not know whether they would receive a dismissal wage. When recoding the answer “don’t know” into “missing”, the internal consistency of this scale rose to Cronbach’s alpha = .67. Moreover, the dropout analyses showed a slightly higher EPRES score for completers vs non-completers. Women with more precarious working conditions might have been particularly motivated to take part in the study to promote change within the workplace for pregnant women.
Since outcomes and consequences of PPD on the ones affected, their families, and especially their children are considered to be severe, a longitutinal approach including risk and protective factors is necessary to provide the best basis for effective treatment approaches. Therefore, work-related factors need to be considered when screening for PPD or during treatment of PPD. Future analyses should include more confounding variables, such as social support and paternal mental health.
WPC should be lowered, especially considering the upcoming changing private situation of women during the perinatal period. The finding that WPC remained significantly associated with PPD when controlling for other psychosocial stress factors at work highlights the importance of introducing strict work guidelines to prevent employers working from home after working hours. Previous research suggests that various family-specific support systems, such as family friendly organizational policies and climate can reduce WPC (65). A growing body of research has investigated family-supportive supervisors, i.e., supervisors at work who promote the management of work and non-work responsibilities and acknowledge their employees private life (66, 67). The concept might be an effective approach for improving employee work, family, and health outcomes (66). Additionally, mindfulness and self-monitoring trainings (68) as well as cognitive-behavioural interventions such as coaching sessions (69) have recently been investigated to successfully reduce WPC.
Further, reward at work seems to be a protective factor against symptoms of PPD for expecting mothers. Women could experience less appreciation and reward at work in their peripartum period due to changing physical capacity and shifting priorities away from the job. Valuing the efforts spent at work during late pregnancy might protect mothers from PPD symptoms and additionally prepare them for a better re-entry into employment after maternity leave.
Some factors of precarious employment, especially defenselessness to authoritarian treatment and low or insufficient wages, seem to increase the risk for PPD. Therefore, special workplace policies are necessary. Julià, Vives, Tarafa, & Benach (19) suggested a surveillance system to monitor different precarious employment dimensions and identify populations at risk to reduce mental health impact. Moreover, the high association of wages with PPD compared to the other factors in this study raises the discussion of equal payment for women in relation to men. It is especially interesting that lower wages in more educated women are associated with an increased risk for PPD.