Examining the Factors that Moderate and Mediate the Effects on the Relationship between Depression and Anxiety and Major Pregnancy Complications and Birth Outcomes
Background Depression is one of the common mental illnesses among women during their child bearing age. Though there is a high level of comorbidity, anxiety is often more prevalent than depression across pregnancy which complicate the pregnancy and birth outcomes. Given potential adverse consequences of depression or anxiety, little is known about the interaction effects as well as causal directionality of the risk factors for pregnancy complications and negative birth outcomes. Thus, the present study will explore the specific roles of the risk factors either as a moderator or as a mediator on the relationship between depression and anxiety and major pregnancy complications and poor birth outcomes. Moderator is defined as an independent variable which influences the strength or the direction of a relationship. On the other hand, mediator variable is defined as an explanatory link and conceptualized as a mechanism to better understand the relationship between a predictor and outcome variable in direct or indirect pathways. The objective of this paper is to understand how the relationship between depression or anxiety, and pregnancy complications and poor birth outcomes could be modified or mediated by other variables. The longitudinal and prospective nature of this study will allow us to examine the moderating and mediating effects more accurately at different time points. Therefore, the current thesis will add empirical evidence on moderating and mediating effects of the risk factors for pregnancy complications and birth outcomes. The findings of this study will be helpful for caregivers and health care professionals in shaping better interventions for women with mental health issues in pregnancy with the aim for bringing about total well-being of the mother. Methods Secondary data was used from the Feelings in Pregnancy and Motherhood (FIP) study. The study included a cohort of 646 high-risk women in Saskatoon. The participants were invited to take part in longitudinal follow up at 3 times: Time 1 = early pregnancy (17.4 ±4.9 weeks), Time 2 = later pregnancy (30.6 ±2.7 weeks) and time 3 = once after their babies were born (4.2 ±2.1 weeks). Self-reported data were collected through face to face interview. Edinburgh Postnatal Depression Scale (EPDS) was used to assess the depression and anxiety. Depression and anxiety are considered as primary predictors while pregnancy complications and poor birth outcomes as outcome variables. For moderation and mediation analysis, sociodemographic factors such as age, education, income, ethnicity, abuse are examined as moderator variables. Behavioural and psychosocial factors are considered as mediator variables. A series of logistic regression analysis was used to analysis the moderation and mediation effects. Results In bivariate analysis, our results found that pregnancy complications and negative birth outcomes were significantly associated with depression, anxiety, education, income, marital status, ethnicity, abuses, social support, smoking, exercise, drinking alcohol, stress, quality of relationship with the current partner, in both the early and the late pregnancy. In mediation analysis, stress in late pregnancy was found to be partially mediating the pathway between depression and pregnancy complications. Moreover, stress showed a full mediation effect on the relationship between anxiety and pregnancy complications. In modelling moderating effects, women who reported depression or anxiety were more likely to have pregnancy complications if they also had experienced sexual abuse before or during early pregnancy, compared to those who did not. Women who reported anxiety in early pregnancy were more likely to experience pregnancy complications if they were non-partnered compared to partnered women. In moderating analysis, in late pregnancy, sexual abuse, emotional abuse, ethnicity and age of the mother were identified as significant moderators. The findings suggest that sexually abused women who experienced depression or anxiety in their late pregnancy were more likely to report more than one pregnancy complications. Similarly, younger mothers were more likely to report anxiety in their late pregnancy resulting in more obstetric complications. Moreover, emotional abuse and ethnicity significantly moderated the relationships between depression or anxiety and poor birth outcomes (i.e. preterm delivery and low birth weight). Conclusion This study provides greater detail about how the risk factors during pregnancy may affect the relationships between maternal mental illness and adverse consequences. Results of this study could inform clinicians who treat and manage women during pregnancy and also promote targeted prevention and intervention programs. Finally, in light of this study, effective community intervention could help to improve physical and psychological well-being of both mother and baby, during and after pregnancy.
Depression, Anxiety, Moderating effect, Mediating Effect, Pregnancy complications, Birth outcomes
Master of Science (M.Sc.)
Community Health and Epidemiology
Community and Population Health Science