Psychiatric Illness, Not Antidepressants, Associated With Breast Milk Insufficiency

Results from a retrospective cohort study published in the British Journal of Clinical Pharmacology found that psychiatric illness, not the use of serotonin reuptake inhibitors, predicted low breast milk supply in mothers of preterm infants.

The investigators identified 3024 preterm births at the Women’s and Children’s Hospital in South Australia between 2004 and 2008, including vaginal deliveries and emergency and elective caesarean section deliveries. Internal administrative data on the mothers were used to determine the dispersal of serotonin reuptake inhibitors during the second and third trimesters (n=86). An additional 126 participants had a diagnosis of psychiatric illness but no serotonin reuptake inhibitor exposure, while 2812 participants had neither a diagnosis nor exposure.

Individuals with antipsychotic or other antidepressant exposure were excluded from the study.

Inadequate milk supply was determined by the dispersal of domperidone, a dopamine D₂ receptor antagonist used to promote lactation. More than half the prescriptions occurred within the first 3 postpartum weeks. In these initial weeks, rates of dispersal were comparable among women with late-pregnancy serotonin reuptake inhibitor exposure and those with unmedicated psychiatric illnesses. Notably, after 3 weeks, use tapered off in the serotonin reuptake inhibitor group, but not in the group with illness alone.

Two sensitivity analyses — births in 2008 alone and first births — showed no significant variation among mothers with psychiatric illness, regardless of exposure status. Nonetheless, women diagnosed with depression were overall significantly more likely to be dispensed domperidone.

The findings stood out from those of previous studies, which introduced the possibility that serotonin reuptake inhibitors might be related to an insufficiency of breast milk.

The investigators noted that, as the study only took into consideration preterm births, the results might not be generalizable to full-term births. The study also lacked clinical confirmation of antidepressant exposure and did not take into consideration illness severity.

Although the applicability of these early findings is still limited, the authors encouraged healthcare providers to consider that mothers struggling with depression may “benefit from additional breastfeeding education and support.”

Reference

Grzeskowiak LE, Leggett C, Costi L, Roberts CT, Amir LH. Impact of serotonin reuptake inhibitor use on breast milk supply in mothers of preterm infants: a retrospective cohort study [published online March 9, 2018]. Br J Clin Pharmacol. doi:10.1111/bcp.13575