ABSTRACT:This cross-sectional study investigated the impact of pregestational overweight and obesity on periodontal status of patients with gestational diabetes mellitus (GDM). Sixty pregnant women with gestational diabetes mellitus (GDM) were recruited for the study. According to the pregestational body mass index (BMI), patients were classified into 3 groups: normal, overweight or obese. The periodontal assessment parameters were the presence of gingival bleeding (GB) and bleeding on probing (BOP) per tooth. Clinical attachment loss (CAL) was assessed per tooth and classified according to following values: 1) absence of attachment loss; 2) between 1 and 2 mm, 3) between 3 and 5 mm; and 4) CAL ≥ 6 mm. The means of individual percentage of teeth with GB and BOP and the means of the individual classified values of CAL were compared through ANOVA. Differences between the groups were established through post hoc Bonferroni test for multiple comparisons (p < 0.05). The analysis revealed significant differences between the normal group and the obese group considering GB (52.76% ± 27.99% and 78.85% ± 27.44%, respectively) and CAL (2.21 ± 0.41 and 2.61 ± 0.54, respectively). Although an increase was found in BOP as the BMI increased (ranging from 55.65% to 75.31%), no statistically significant differences were found among the groups. Patients with GDM and pregestational obesity had significantly more gingivitis and periodontal attachment loss that those with normal pregestational BMI. Periodontal treatment should be considered in the establishment of future recommendations for metabolic control for this special group of patients. DESCRIPTORS: Diabetes, gestational; Obesity; Gingivitis; Periodontitis; Oral manifestations. RESUMO:O objetivo do presente estudo foi examinar o efeito da massa corporal prévia à gestação (IMC -índice de massa corpórea) sobre o periodonto de pacientes com diabete mellitus gestacional (DMG). A amostra constituiu-se de 60 gestantes classificadas em 3 grupos segundo o IMC: normal, sobrepeso ou obeso. Os parâmetros de avaliação periodontal foram sangramento gengival (SG), sangramento à sondagem (SS) e perda de inserção clínica periodontal (PI) categorizada de acordo com os seguintes valores: 1) correspondente à ausência de perda de inserção; 2) PI entre 1 e 2 mm, 3) PI entre 3 e 5 mm; e 4) PI ≥ 6 mm. Médias das porcentagens dos dentes com SG e SS e as médias dos valores categorizados, por dente, da perda de inserção foram comparadas por meio do teste ANOVA e as diferenças entre os grupos foram estabelecidas por meio do teste post hoc de Bonferroni para comparações múltiplas (p < 0,05). Diferenças estatisticamente significantes foram identificadas entre o grupo normal e obeso com relação às médias percentuais da presença de SG (52,76 ± 27,99% e 78,85 ± 27,44%, respectivamente) e às médias da categorização da PI (2,21 ± 0,41 mm e 2,61 ± 0,54 mm, respectivamente). Embora tenha se observado aumento no percentual médio de SS à medida do incremento do IMC, não foram observadas diferenças estatisticament...