Abstract
OBJECTIVE: to analyze maternal knowledge about infant development and its matching to the care offered to children during their first year of life. METHOD: a longitudinal and prospective study, in the stages of pregnancy and of the child's 12th/13th month of life. Interviews were applied to 121 women in a Brazilian city, based on 21 items selected from the Knowledge of Infant Development Inventory, related to the first year of life. Calculation of rates of correct answers was used, as well as regression by Ordinary Least Squares and White's standard error. RESULTS: the participants who answered correctly more aspects have more years of study, are older and present high family incomes. When the "having a partner or not" variable was considered, the correct answers presented a discrete fluctuation. Regarding the themes, there were more correct answers to aspects about health, safety and infant development milestones. Primiparous mothers were more likely to wean, overprotect and have children using electronic devices, and less likely to seek information about child care. CONCLUSION: there was matching between some maternal knowledge and execution of child care. The connection between them is relevant to indicate in detail the unknowns and uncertainties and to improve positive knowledge, contributing to promoting early childhood development.