Relapse in the first three months postpartum in women with history of serious mental illness

Relapse of serious mental illness (psychotic and bipolar disorders; SMI) in the postpartum period is potentially devastating for mother and baby. There is limited evidence on whether medication in the perinatal period is protective against postpartum relapse for women with SMI particularly non-affective psychoses. We aimed to investigate risk factors for postpartum relapse, particularly the potential prophylactic effects of medication. Using an anonymised resource of comprehensive electronic secondary mental health care records linked with maternity data, women with history of SMI who gave birth from 2007 to 2011 were identified. Relapse was defined as admission to acute care in the first 3 months postpartum. Women who were exposed to regular medication were compared with women who were unexposed. Data were analysed by pregnancy using random effects models to account for repeated measures in women who had more than one pregnancy in the study period. There were 452 full term pregnancies, of which 128 (28.3%) were associated with relapse in the first 3 months postpartum, with recent relapse an independent predictor (aOR; 95% CI:1.30–2.27). There was no evidence of a prophylactic effect of medication (crude OR = 0.65; 0.34–1.25) (aOR = 0.99; 0.54–1.83), in women with non-affective or affective psychoses (interaction test p = 0.453). Recent relapse increases the risk of relapse in the postpartum period so women with severe illnesses with a recent history of relapse should be warned pre-conception about the high risk of relapse. The lack of evidence of a protective impact of medication prophylaxis may reflect confounding by indication.