Risk factors for incident peripartum mental illness in multiple sclerosis

Background — Mothers with MS face an increased incidence and prevalence of peripartum mental illness as compared to mothers without MS.

Objective — To determine the factors associated with the risk of peripartum mental illness among mothers with MS.

Methods — We identified mothers with MS with live births between 2002 and 2019 using linked population-based administrative data from Ontario, Canada. Using validated definitions, we estimated the incidence of mental illness (depression, anxiety, bipolar disorder) from conception through the first post-partum year (peripartum period). We used multivariable Poisson regression to assess the association between age, delivery year, area-level deprivation (Ontario Marginalization Index), disease duration, disability, and comorbidity and incidence of peripartum mental illness.

Results — Among 1745 mothers with MS, the mean (SD) age at conception was 31.2 (4.8) years. Mothers living in communities that lacked cohesion had increased rates of peripartum depression (incidence rate ratio [IRR] 1.25; 1.11–1.42) and anxiety (IRR 1.20; 1.07–1.33). Elevated MS disability level was associated with elevated peripartum depression rates (IRR 1.51; 1.12–2.04).

Conclusion — Higher area-level deprivation and disability levels are associated with an increased incidence of peripartum mental illness. These findings may assist clinicians in identifying women with MS who may benefit from peripartum mental health support.