(277) Lower Rates of Initiation of Breastfeeding and Exclusive breastfeeding in Women Treated with Chronically Used Anti-inflammatory Medications

Background: Breastmilk is the recommended sole source of nutrition in the first 6 months of life. Mothers who require chronic medications may be advised or choose not to breastfeed due to lack of safety data.

Objectives: To determine if new mothers being treated with chronically used medications are less likely to follow recommended breastfeeding practices than mothers not using such medications.

Methods: Pregnant women from United States and Canada were enrolled in the prospective MotherToBaby-cohort between 2010 and 2022. Women with medications with potential to harm were excluded. Studied exposures were 1) anti-inflammatory drugs including immunomodulators and systemic steroids, 2) selective serotonin reuptake inhibitor antidepressants, 3) asthma drugs including inhaled steroids and long-acting beta-agonists and 4) no chronic medications at delivery. Outcomes were not initiating breastfeeding, supplementing with formula within two weeks after delivery and stopping breastfeeding before six months. Risks were calculated with modified Poisson and Cox regressions, adjusted for a propensity score composed of year of delivery, parity, socioeconomic status, body mass index, race, and ethnicity.

Results: The sample included 799 anti-inflammatory drug exposed, 293 antidepressant exposed, 217 asthma drug exposed and 4439 unexposed women. Mothers taking anti-inflammatory drugs were more likely to not initiate breastfeeding (adjusted Risk Ratio [aRR] 4.01; 95% Confidence Interval [CI] 3.10-5.18), to supplement with formula (aRR 1.14; 95% CI 1.02-1.27) and to stop breastfeeding before six months (adjusted Hazard Ratio [aHR] 1.73; 95% CI 1.29-2.32). Mothers taking antidepressants were more likely to supplement with formula (aRR 1.25; CI 1.10-1.42) but initiated and continued breastfeeding for six months to the same extent as the unexposed. Mothers with asthma drugs had an increased risk of stopping breastfeeding before six months (aHR 1.73, 95% CI 1.003-2.98), but not for the other outcomes.

Conclusions: Women chronically treated with immunomodulators and systemic steroids were more likely to not breastfeed, to supplement with formula and to stop breastfeeding before six months. Many new therapeutics were approved for chronic inflammatory diseases in the last two decades without adequate safety data in lactation. Timely development and dissemination of safety data is needed to support better clinical decision-making regarding breastfeeding.