A Population-Based Cohort Study of Early Infant Feeding Initiation in Maternal Bipolar Disorder.

OBJECTIVE: In maternal bipolar disorder, decisions about early infant feeding are complex, and may depend on maternal mental health stability, sleep protection needs, and medication safety in lactation. We aimed to explore early infant feeding practices in this population. METHODS: This population-based cohort study in Ontario, Canada (2012-2018) compared mothers/birthing parents with bipolar disorder (n = 11,398), depressive and/or anxiety disorders (n = 209,929) and no mood or anxiety disorder (referent, n = 417,588) on exclusive feeding with breastmilk at hospital discharge (primary outcome), breastfeeding intention, early skin-to-skin contact and initiation of breastfeeding, and in-hospital breastfeeding support. Within mothers/birthing parents with bipolar disorder, we compared those prescribed each of antidepressant, antipsychotic, valproic acid, lithium, or other antiepileptic monotherapy and 2 or more of these medications (polypharmacy) to those not prescribed any of these medications. Modified Poisson regression generated relative risks (RR, 95% CI) adjusted for socio-demographics and clinical characteristics. RESULTS: Maternal bipolar disorder was associated with reduced exclusive feeding with breastmilk at discharge (57.4% vs. 62.3% in the referent, aRR 0.95, 95% CI 0.93-0.98), but maternal depression and/or anxiety disorder was not. Bipolar disorder was also associated with reduced intention to breastfeed (88.5% vs. 94.1%), early skin-to-skin contact (79.2% vs. 81.0%) and in-hospital breastfeeding support (88.9% vs. 94.4%) compared to those with no mood or anxiety disorder. Among those with maternal bipolar disorder, lithium and polypharmacy were each associated with reduced likelihood of the outcomes compared to those not prescribed any psychotropic medication; antidepressants, antipsychotics, and antiepileptics were not. CONCLUSIONS: These data support the case for additional supports and services to support mothers with bipolar disorder in early infant feeding initiation, and for research into how to best utilize medications in lactation.