Tobacco and Marijuana Use and Effect on Gestational Weight Gain [A195

Abstract

INTRODUCTION: Previous work has addressed the effect of marijuana and tobacco use in pregnancy on infant birth weight; however, there is a paucity of data reporting the potential impact of marijuana and tobacco use on maternal gestational weight gain (GWG). This study sought to determine an association between marijuana and/or tobacco use and meeting GWG recommendations. METHODS: This retrospective study included patients who delivered at a single academic institution between January 2019 and June 2021. Institutional review board approval was obtained. Data collected included prepregnancy weight, BMI, and gestational weight gain (GWG), as well as tobacco and marijuana use. GWG was categorized according to Institute of Medicine and American College of Obstetricians and Gynecologists recommendations as adequate, inadequate, or excessive. RESULTS: A total of 7,653 patients were included in the study. Polysubstance use was excluded. Overall, 52% of patients experienced excessive GWG, 28% adequate GWG, and 19% inadequate GWG. Former tobacco users were more likely to have excessive GWG than non-smokers and current tobacco users (61% versus 51% and 51%; P<.001), while current tobacco users were more likely to have inadequate GWG than non-users and former tobacco users (24% versus 19% and 15%; P<.001). Marijuana users were more likely to have excessive GWG than non-users (57% versus 52%; P=.007). Marijuana use remained a significant predictor of excessive GWG, even when controlling for tobacco use (P<.035). CONCLUSION: It appears that tobacco and marijuana use may play a role in GWG. Further research is needed in order to fully understand and appropriately counsel on the potential effects of marijuana and tobacco use on GWG and pregnancy outcomes.