BACKGROUND: Despite the WHO and ACOG's recommendations for at least 150 min of weekly moderate-intensity physical activity during pregnancy, adherence remains low, partly due to concerns about safety and efficacy of specific exercise modalities. OBJECTIVE: To evaluate pregnant women's outcome expectancy for maternal and fetal health regarding specific physical activity modalities and the influence of healthcare provider discussions on these perceptions. METHODS: A cross-sectional survey, distributed through Qualtrics (a platform to help design and distribute surveys) and word of mouth of 507 pregnant women assessed perceptions of moderate, vigorous, and resistance activities. Provider discussions and past adverse pregnancy experiences were likewise examined for their influence on outcome expectancy. RESULTS: Walking and yoga were perceived as the most beneficial modalities for both maternal and fetal health, with the outcome expectancies being 9.5 ± 2.1 and 8.8 ± 2.9 for maternal health and 9.0 ± 2.5 and 8.2 ± 3.0 for fetal health. Higher intensity and resistance activities were viewed less favorably, especially CrossFit® resistance training with outcome expectancies being 5.2 ± 3.4 for maternal health and 4.8 ± 3.3 for fetal health. All physical activities were viewed as more beneficial for maternal health than fetal health. Discussions with healthcare providers occurred in over 70 % of cases but did not generally relate to these perceptions. Past adverse pregnancy experiences were not related to statistically significant changes in outcome expectancy. Previously being prescribed bed rest had some weak associations with greater maternal and fetal outcome expectancy for a few physical activity modalities. CONCLUSIONS: Pregnant women's perceptions of health benefits clearly differ based on modality of activity and dependent on whether maternal or fetal health. Targeted communication strategies from healthcare providers and public health efforts are needed to improve perceptions of physical activity during pregnancy, especially for vigorous and resistance activities.