Spontaneous Miscarriage and Social Support in Predicting Risks of Depression and Anxiety: a Cohort Study in UK Biobank

BACKGROUND: It is still unclear whether social support can moderate the high risk of depression and anxiety due to spontaneous miscarriage. OBJECTIVE: This study prospectively investigated the associations of spontaneous miscarriage with risks of depression and anxiety, and evaluated the interactions between spontaneous miscarriage and the degree of social support in relation to depression and anxiety risks. STUDY DESIGN: A total of 179,000 participants from the UK Biobank with pregnancy experience and without depression or anxiety at baseline were included. Spontaneous miscarriage was defined by self-report from participants at enrollment or by International Classification of Diseases codes. The degree of social support was defined as the number of social support factors including living with a spouse or partner, participation in social activities, and confiding. Cox proportional hazards models were used to evaluate the joint association of spontaneous miscarriage and social support with the risks of depression and anxiety. RESULTS: During a median follow-up of 12.3 years, 4939 depression incidents and 5742 anxiety incidents were documented. For participants with 1, 2, and double dagger 3 spontaneous miscarriages, hazard ratios (95% confidence intervals) for depression were 1.10 (1.02-1.19), 1.31 (1.14-1.50), and 1.40 (1.18-1.67), respectively (P trend <.001), compared with participants without a history of spontaneous miscarriage, after adjustment for covariates. For anxiety, the hazard ratios (95% confidence intervals) were 1.07 (1.00-1.15), 1.04 (0.90-1.19), and 1.21 (1.02-1.44), respectively (P trend=.01). Moreover, we found that the risk of depression associated with a combination of spontaneous miscarriage and low degree of social support in later life was greater than the sum of the risks associated with each individual factor, indicating significant interactions on an additive scale (P interaction=.03). CONCLUSION: Spontaneous miscarriage is associated with higher risks of depression and anxiety, and the risk of depression is further increased when there is also low degree of social support.