RESUMEN
Background: Obesity in pregnancy is associated with significantly higher rates of infection. Aim: To compare the infectious morbidity in pregnant women with normal and altered body mass index (BMI). Material and Methods: Cross sectional retrospective study of 6,150 patients who had delivery or second trimester abortion during 2012. The patients were classified according to BMI as underweight, normal weight, overweight and obese. We compared the frequency of pregnancy and perinatal complications related to ascending bacterial infection (ABI). The data was obtained from the hospitals databases. Results: Obese patients had higher rates of pregnancy and perinatal complications related to ABI compared to patients with normal weight. The odds ratios (OR) and 95% confidence intervals (CI) for second trimester abortion were 3.45 (1.63-7.31) p < 0.01, for preterm delivery 2.42 (1.51-3.87) p < 0.01, for labor and puerperium infections 3.42 (2.06-5.68) p < 0.01 and for early neonatal infectious and perinatal mortality 4.46 (1.75-11.37) p < 0.01. A logistic regression analysis revealed that obesity is an independent risk factor for second trimester abortion related to ABI with an OR of 3.18 (CI 95% 1.46-6.91), premature delivery related to ABI with an OR of 2.51 (CI 95% 1.54-4.09) and for delivery and postpartum infections with an OR of 4.44 (CI 95% 2.62 to 7.51). Conclusions: Obese pregnant women had a 2.5 to 4.5 times increased risk of infectious morbidity compared to normal weight patients. Obesity is an independent risk factor for second trimester abortion and preterm delivery related to ABI and delivery and postpartum infectious.