Introduction: Abnormal pregestational and gestational maternal nutritional status is an undeniable health problem which can result in gestational changes and interfere in fetal and maternal health conditions. Objective: To analyze the influence of pre-pregnancy nutritional status on mother-newborn pair outcomes. Methods: This is an observational, analytical, and cross-sectional study carried out in a public Maternity Hospital in Joinville, SC, Brazil. A total of 1,670 puerperal women were interviewed and classified according to BMI. The outcomes evaluated were: cesarean delivery, Gestational Diabetes Mellitus, Pregnancy-induced Hypertension, small for Gestational age newborns, large for gestational age newborns, premature birth, low weight at birth and admission to the neonatal intensive care unit. Results: Low-weight pregnant women had a higher risk of cesarian delivery. Overweight and obese patients had a greater chance of GDM, with the odds ranging from 1.5 to 7.2 times, and PIH with the odds ranging from 1.7 to 4.6 times. Conclusion: Low-weight pregnant women have a higher chance of cesarian delivery. Meanwhile, overweight and all classes of obesity in pregnancy progressively increase the risk of GDM and PIH.