Introduction: Periodontal diseases, especially gingivitis, are the most common oral diseases during pregnancy. Regarding to high prevalence of periodontal diseases in pregnant women as a high risk group and unknown role of blood groups as a possible predisposing factor, this study was done to investigate the relationship between periodontal diseases and ABO blood groups and Rh system in pregnant women.
Methods: This analytical study was carried out on 800 pregnant women (200 pregnant women in each ABO blood groups) in third trimester of pregnancy who were referred to Karaj health centers, Iran, 2010. During the examination, ultrasonographic probe was held in teeth 3, 9, 12, 19, 25 and 28. Periodontal disease index such as modified gingival index and simplified oral hygiene index were measured. Chi-square test was used to determine the relationship between periodontal diseases and ABO blood groups. P value less than 0.05 was considered significant.
Results: There were no significant relationships between periodontal diseases and ABO blood groups and Rh system in pregnant women. Rh negative pregnant women had less periodontal attachment loss (16.2%).
Conclusion: Rh positive pregnant women are considered as the high risk group.