BACKGROUND: Growing evidence suggests that maternal prepregnancy weight and gestational weight gain are risk factors for perinatal complications and subsequent maternal and child health. Postpartum weight retention is also associated with adverse birth outcomes and maternal obesity. Clinical guidelines addressing healthy weight before, during, and after pregnancy have been introduced in some countries, but at present a systematic accounting for these policies has not been conducted. The objective of the present study was to conduct a cross-national comparison of maternal weight guidelines. METHODS: This cross sectional survey administered a questionnaire online to key informants with expertise on the subject of maternal weight to assess the presence and content of preconceptional, pregnancy and postpartum maternal weight guidelines, their rationale and availability. We searched 195 countries, identified potential informants in 80 and received surveys representing 66 countries. We estimated the proportion of countries with guidelines by region, income, and formal or informal policy, and described and compared guideline content, including a rubric to assess presence or absence of 4 guidelines: encourage healthy preconceptional weight, antenatal weighing, encourage appropriate gestational gain, and encourage attainment of healthy postpartum weight. RESULTS: Fifty-three countries reported either a formal or informal policy regarding maternal weight. The majority of these policies included guidelines to assess maternal weight at the first prenatal visit (90%), to monitor gestational weight gain during pregnancy (81%), and to provide recommendations to women about healthy gestational weight gain (62%). Guidelines related to preconceptional (42%) and postpartum (13%) weight were less common. Only 8% of countries reported policies that included all 4 fundamental guidelines. Guideline content and rationale varied considerably between countries, and respondents perceived that within their country, policies were not widely known. CONCLUSIONS: These results suggest that maternal weight is a concern throughout the world. However, we found a lack of international consensus on the content of guidelines. Further research is needed to understand which recommendations or interventions work best with respect to maternal weight in different country settings, and how pregnancy weight policies impact clinical practices and health outcomes for the mother and child.