Peripartum mental illness in serial pregnancies in mothers with multiple sclerosis and other chronic diseases

BACKGROUND: Mothers with multiple sclerosis have an elevated risk of peripartum mental illness, but changes in risk across serial pregnancies are unknown. OBJECTIVES: We compared the incidence, lifetime prevalence, and prevalence of peripartum mental illness requiring care ('active') among mothers with multiple sclerosis and other conditions. METHODS: Using population-based administrative data from Ontario, Canada, we identified 549,010 mothers with multiple sclerosis (922), epilepsy (3486), inflammatory bowel disease (3008), diabetes (5991), and without these diseases (comparators, 535,603) who had two live births. Using validated definitions, we estimated incidence and prevalence of mental illness (any, depression, anxiety, bipolar disorder, psychosis, substance use, suicide attempt) during serial peripartum periods. We compared rates using Poisson models. RESULTS: Among mothers with multiple sclerosis, any incident mental illness affected 20.4% during the first peripartum period and 11.6% in the second; one-quarter received any mental illness care (active prevalence) during the second peripartum period. Post-adjustment, mothers with multiple sclerosis had a higher active prevalence of depression (prevalence ratio 1.19; 1.04-1.35), anxiety (prevalence ratio 1.21; 1.09-1.35), and bipolar disorder (prevalence ratio 1.48; 1.28-1.71) than comparators, as did mothers with epilepsy, inflammatory bowel disease and diabetes. CONCLUSIONS: Mothers with multiple sclerosis, epilepsy, inflammatory bowel disease and diabetes share an elevated risk of mental illness in serial pregnancies.