Supplementary Material for: Why and how to improve nutritional care for pregnant women after bariatric surgery? the NUMASURG Study Protocol

Introduction: Pregnancies after bariatric surgery (BS) are considered at risk because of increased rate of maternal micronutrient deficiencies, small-for-gestational age and prematurity. Longer-term data on child health are scarce and conflicting. The objective of the NUMASURG project is to understand the consequences of micronutrient deficiencies during pregnancy after BS for the mother and the offspring and to better document the child’s health outcomes after maternal BS. Methods: NUMASURG is a collaborative project bringing together clinicians, biologists, epidemiologists, clinical researchers and the French Obesity Research Center of Excellence network. The project is organized into four specific tasks: 1) establish a cohort of 1000 pregnant women with a history of BS; 2) establish reference values for nutritional biomarkers during pregnancy (vitamins A, B9, B12, 25(OH)-D, zinc, ferritin) from two birth cohorts of the French general population (EDEN and ELFE); 3) compare the nutritional status between pregnant women after BS and women from the general population and investigate the associations between nutritional biomarkers and small-for-gestational age and prematurity in both populations; and 4) describe the health of children born from mothers with a history of BS using the French national health data system. Started in September 2023, the project will run for 4 years. Conclusion: The NUMASURG project will allow for implementing updated recommendations concerning the monitoring and nutritional supplementation of pregnant women with a history of BS. The ultimate objective is to improve the nutritional status of these women and consequently, limit the main risks currently observed during pregnancy after BS. Structuring a clinical database will help standardize practices and enable future research projects in this area, and will be a key first step in creating a prospective cohort of children born from mothers with a history of BS.