Objective: to study the frequency of medication use in the immediate postpartum period and to evaluate possible effects on breastfeeding. Methods: a cross-sectional study was carried out with 2,173 women that gave birth in four hospitals in Belo Horizonte, a city in the southeast of Brazil, between July 1998 and July 1999. The sample was calculated by means of the data obtained from the City's Health Department according to the number of labors made in these four hospitals in 1995, which amounts to approximately 5% of the total number that usually occurs within a year. Women were randomized according to the calendar of epidemiological weeks. The interviews consisted of a questionnaire through which information about breastfeeding and sociodemographic data were obtained. In addition, the data were collected from mothers' and newborns' medical records. The drugs were classified according to their compatibility and incompatibility with breastfeeding, and were monitored as to the possible adverse effects on newborn infants.Results: 2,090 (96.2%) of 2,173 women received drug therapy in the immediate postpartum period. Among the drugs used, 2,054 (98.3%) were not contraindicated for breastfeeding; 338 (16.2%) did not contain safe information, and 3 (0.14%) were contraindicated. Conclusions: although drug therapy was widespread among the mothers followed up at these four hospitals, there seems to be no influence on breastfeeding. Fortunately, most prescribed drugs did not interfere with mothers' and infants' health.
breast feeding; human milk; drugs; adverse effects
