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 179000 participants with pregnancy experience and free of depression or anxiety at baseline from the UK Biobank were included. Spontaneous miscarriage was defined by self-report from participants at enrollment or by the ICD 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 hazard models were used to evaluate the joint association between spontaneous miscarriage and social support on 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. After adjustment for covariates, compared with participants without a history of spontaneous miscarriage, hazard ratios (95% confidence interval, CI) for depression were 1.10 (1.02-1.19), 1.31 (1.14-1.50) and 1.40 (1.18-1.67) for participants with the number of spontaneous miscarriages of one, two, and three or more, respectively (P-trend <0.001). For anxiety, the HRs (95% CI) were 1.07 (1.00-1.15), 1.04 (0.90-1.19), and 1.21 (1.02-1.44), respectively (P-trend =0.01). Moreover，we found the risk of depression associated with a combination spontaneous miscarriages and low degree of social support in later life was greater than the addition of the risk associated with each individual factor, indicating significant interactions on an additive scale (P-interaction = 0.03). Conclusion Spontaneous miscarriage is associated with higher risks of depression and anxiety and shows an additive interaction with the low degree of social support on the risk of depression.