Introduction: We described calls to U.S. poison centers (PCs) related to potential exposure to substances through breast milk. Materials and Methods: We analyzed National Poison Data System calls between 2001 and 2017 with "Exposure through breast milk" or "Drug use during breastfeeding" as the coded scenario. Data handling and descriptive statistics were carried out using SAS JMP 12.01. Results: U.S. PCs received 76,416 information calls and 2,319 exposure calls related to breast milk. Exposure calls were from a residence in 76% (n = 1,758), from health care facilities (HCFs) in 15.5% (n = 360), and from a workplace in 0.6% (n = 15). A total of 466 exposures (20.1%) were subsequently managed at a HCF: 269 were evaluated and released (58%), 38 were admitted to intensive care unit (8.2%), and 53 were admitted to hospital floor (11%). Medical outcomes included 1 death (0.04%), 8 major effect (0.3%), 43 moderate effect (1.9%), 170 minor effect (7.3%), and 390 no effect (16.8%). Exposure calls that reported major effects involved opioids, benzodiazepines, ethanol, cyclobenzaprine, insulin, and amphetamines. Exposure calls most commonly involved antibiotics, antifungals, benzodiazepines, opioids, and selective serotonin reuptake inhibitors (SSRIs). A total of 1,192 exposures (51.4%) had reported signs/symptoms including drowsiness, agitation, rash, and vomiting/diarrhea. Information calls most commonly involved systemic antibiotics, SSRIs, antihistamines, corticosteroids, and benzodiazepines. Conclusions: Substances common to both exposure and information calls included antibiotics, benzodiazepines, and SSRIs. Most cases of severe toxicity included potential exposures through breast milk to benzodiazepines and opioids. These data may help inform educational outreach, risk assessment, and bedside care for breastfeeding mothers.
Keywords: breastfeeding; exposures; information calls; poison centers; poisoning.