This study aimed to evaluate the impact of selected pregnancy pathologies statistically depending on overweight/obesity and excessive maternal weight gain during pregnancy on women who gave birth in the years 2013-2015 at the Second Department of Gynecology and Obstetrics at the University Hospital in Bratislava, Slovakia. In a retrospective study, we analyzed data gathered from the sample, which consisted of 7122 women. Our results suggest a statistically significant, higher risk for the groups of women with overweight and obesity and gestational hypertension (adjusted odds ratio (AOR) = 15.3; 95% CI 9.0-25.8 for obesity), preeclampsia (AOR = 3.4; 95% CI 1.9-6.0 for overweight and AOR = 13.2; 95% CI 7.7-22.5 for obesity), and gestational diabetes mellitus (AOR = 1.9; 95% CI 1.2-2.9 for overweight and AOR = 2.4; 95% CI 1.4-4.0 for obesity). A higher incidence of pregnancies terminated by cesarean section was observed in the group of obese women. Gestational weight gain above IOM (Institute of Medicine) recommendations was associated with a higher risk of pregnancy terminated by C-section (AOR = 1.2; 95% CI 1.0-1.3), gestational hypertension (AOR = 1.7; 95% CI 1.0-2.7), and infant macrosomia (AOR = 1.7; 95% CI 1.3-2.1). Overweight and obesity during pregnancy significantly contribute to the development of pregnancy pathologies and increased incidence of cesarean section. Systematic efforts to reduce weight before pregnancy through prepregnancy dietary counseling, regular physical activity, and healthy lifestyle should be the primary goal.