(225) Medication Use Among Lactating Persons: An Electronic Health Record (EHR)-Based Approach

Publication Number: 556

Background: There have been few published studies on the prevalence of medications used by lactating persons and they have been limited by small size, selection bias, and lack of information on infant age.

Objectives: Using a novel, electronic health record (EHR)-based approach, to estimate the prevalence of medication use at 2, 4, and 6 months postpartum among lactating mothers.

Methods: We utilized automated EHR data from a US health system to conduct a retrospective cohort study. To classify lactation status among postpartum persons, we used infant feeding information (breast milk only, formula or other milk only, or both) at well-child visits (WCV) and maternal breastfeeding status at postpartum visits (yes, no). This information is routinely recorded in standardized fields in the health system’s EHR. To identify maternal medication use, we used dispensing data from pharmacy benefit managers and pharmacies via Surescripts® health information network. We linked mothers receiving prenatal care within the health system to their infants born between May 2018 and June 2019 and required infants to have at least one WCV between 31-90 days of life (i.e., 2-month WCV). We included mothers of infants who received breastmilk at 2-month WCVs and excluded mothers reporting no breastfeeding at postpartum visits. Mothers were excluded when infants were not receiving breastmilk at WCVs. We assessed maternal medications dispensed between 17-90, 77-150, and 137-210 days after delivery corresponding to 2, 4, and 6-month WCV less a two-week grace period (to allow for continued use of medications dispensed just before the WCV).

Results: We identified 6,049 eligible mothers, and 4,181 (69.1%) were classified as lactating at the 2-month WCV. Among the lactating mothers, 62.7% were Non-Hispanic White and 31.4% had public insurance. The most common medication classes dispensed between 17-90 days postpartum were oral progestin contraceptives (19.3%), selective serotonin reuptake inhibitors (9.1%), first generation cephalosporins (4.3%), thyroid hormones (3.6%), nonsteroidal anti-inflammatory agents (3.4%), penicillinase-resistant penicillins (3.1%), topical corticosteroids (2.9%), and imidazole-related antifungals (2.1%). The most common medication classes were similar at 77-150 days and 137-210 days postpartum.

Conclusions: Progestin-only contraceptives, antidepressants, and antibiotics were among the most commonly dispensed medications among lactating mothers. With routine collection of breastfeeding information, mother-infant linked EHR data may overcome small size and volunteer bias that have challenged previous studies of medication utilization during lactation. These data have the potential to be used to study medication safety during lactation.