Effect of counseling on maternal reporting of adverse effects in nursing infants exposed to antibiotics through breast milk

In a recent trial, we found that nursing women reported diarrhea in their nursing infants after maternal use of antibiotics. However, because they were told that this could occur during a medication counseling session, the observed effect could have been due to a reporting bias. The objectives of this study were to determine if counseling nursing women about side effects of antibiotic they used could (a) influence the adverse event reporting rate or (b) influence maternal nursing and medication compliance behavior. In a randomized, controlled trial, nursing women calling a teratogen information service for advice about selected antibiotics received one of two possible counseling formats (A and B). Both groups were informed that the antibiotics were safe to use. Mothers in group B were also informed about a theoretical risk of diarrhea in the infant. Mothers later reported clinical events they noted in the infants and judged whether they were due to the antibiotic. Eighty-seven percent ( 54 62) of group A subjects compared to 68% ( 52 76) of group B subjects reported clinical events in their infants during their antibiotic therapy (P = 0.017). The incidence of reported diarrhea was 26% in group A compared to 17% in group B (P = 0.3); 34% of subjects in both groups attributed clinical events to antibiotic therapy (P = 1.0). Diarrhea was attributed to antibiotic therapy in 13% of group A and 12% of group B subjects (P = 1.0). No differences were observed between groups in breastfeeding pattern and antibiotic compliance. Breastfeeding women counseled about adverse effects were not more likely to report side effects in their infants or to change nursing behavior and medication compliance.