Medical guidelines apply broadly to individuals with obesity. Using provincial records linking maternal and newborn outcomes, this study stratified 317,958 pregnancies between 2008-2018 births in British Columbia by WHO body mass index categories, then further stratified using a perinatal adaptation of the Edmonton Obesity Staging System (EOSS) which categorizes obesity using related co-morbid disease. EOSS stage 0 has no co-morbid disease, stage 1 has subclinical symptoms such as hyperlipidemia. Stage 2 includes obesity-related co-morbidities such as hypertension or diabetes. Stage 3 has obesity-related end organ disease exemplified by heart disease. EOSS stage 4 has severe end organ disease such as renal failure. The attached poster shows results.