Many normative beliefs are shared and learned through interpersonal communication, yet research on norms typically focuses on their effects rather than the communication that shapes them. This study focused on interpersonal communication during pregnancy to uncover (a) the nature of pregnancy-related communication and (b) normative information transmitted through such communication. Results from interviews with pregnant women living in rural Mexico revealed limited social networks; often, only a woman's mother or the baby's father were consulted about prenatal care decisions. However, women also indicated that communication with others during pregnancy provided important normative information regarding prenatal care. First, most referents believed that women should receive prenatal care (injunctive norm), which was conceptualized by participants as biomedical, nonmedical, or a blend of both. Second, family members often received prenatal care, whereas friends did not (descriptive norms). These findings highlight the key role of personal and social networks in shaping personal pregnancy-related beliefs and behaviors.