BackgroundPeriodontal disease is considered as a risk factor for poor pregnancy outcomes, including preterm birth and low birth weight. Only few studies have assessed the knowledge and practice behaviours of healthcare providers, concerning oral health during pregnancy, periodontal diseases and their role in adverse pregnancy outcomes. The present study aimed to compare the knowledge and practice behaviours of a group of Iranian obstetricians, general practitioners, and midwives about periodontal disease.Design and methodsA cross-sectional study was conducted using a self-administered, structured questionnaire that was previously used in North Carolina. The questionnaire was translated into Persian language and was randomly distributed among 200 obstetricians, general practitioners, and midwives participating in an international congress. Data were analysed by Chi-square and spearman correlation tests using SPSS statistical software (version PASW 18).ResultsA total of 150 completed the questionnaires, achieving a response rate of 75%. Totally, the knowledge of the obstetricians was more accurate compared to the two other groups and the midwives were the worst. More experienced general practitioners (P=0.002) and obstetricians (P=0.049) did less dental examinations for their patients during their first visit or periodically. More experienced obstetricians also referred their patients for dental examinations during pregnancy less than their less experienced colleagues (P<0.001).ConclusionsAlthough the participants had some knowledge about periodontal disease and its association with adverse pregnancy outcomes, there is much space for improvements. The participants’ attitude and knowledge were consistent.Significance for public healthPreterm labour and low birth weight are considered to be one of the greatest problems in obstetrical medicine and are one of the most prevalent risk factors for death during the neonatal period. On the other hand, periodontal diseases are considered as important factors affecting pregnant women and their new-born children. Therefore it seems quite important to find out whether the healthcare providers who are most visited by pregnant women are aware of the periodontal disease and its relationship with poor pregnancy outcomes. The present study aimed to assess and compare the knowledge and beliefs of a group of Iranian obstetricians, general practitioners, and midwives regarding periodontal disease, and to assess whether their practice behaviours reflected their beliefs. The authors hope that publication of this paper would provide an evidence to plan for these health professionals’ education on the importance of pregnant women’s oral health promotion.