The vast majority (50-75%) of youth (≤ 21 years old) who become pregnant gain more weight during pregnancy than is recommended by the National Academy of Medicine. Excess weight gain during pregnancy is a strong risk factor for long term obesity among mothers and their infants. There is a significant gap in our understanding of youth's knowledge and behavior related to weight gain during pregnancy. In order to develop effective interventions for pregnant youth, it is necessary to understand their distinct needs and preferences. Using a youth-centered qualitative approach, the purpose of this study was to explore the knowledge, behaviors, and social factors that influence weight gain during pregnancy for youth.Participants completed weekly text message surveys and semi-structured interviews to explore their perspectives of weight gain during pregnancy. Data were analyzed using qualitative thematic analysis based on grounded theory.Pregnant youth ages 16-24 years old.Among our sample (n=54) four themes emerged. First, many youths were knowledgeable about healthy behaviors in pregnancy. However, the second theme showed that many youths reported barriers to engaging in these healthy behaviors, including stress, poor motivation, and issues of convenience. Third, they demonstrated inadequate knowledge about exercise in pregnancy, and fourth, many endorsed food cravings that significantly influenced diet choices.Many pregnant youths have appropriate knowledge about healthy behaviors during pregnancy, but face many youth-specific barriers to achieving these behaviors. Interventions should address logistical challenges (e.g. food access, cost, transportation) to healthy behaviors in pregnancy to make healthy diet and exercise more convenient for pregnant youth.