BACKGROUND: The effects of sociocultural status on periodontal conditions in pregnant women have been reported by a number of researchers and there have been speculations about the effects of hormonal changes, patients' systemic health, and socio-cultural characteristics on periodontal health during pregnancy. METHODS: This study evaluates the periodontal condition of 61 pregnant women at their first, second, and third trimesters, and the relation between the demographic (age, professional level, education) and clinical variables (previous periodontal care, frequency of tooth brushing). The clinical indices, including plaque index, gingival index, and probing depth measurements were repeated at the first, second, and third trimesters. The statistical tests used were stepwise analysis and paired sample test. RESULTS: The results of the study showed that the plaque index, gingival index, and probing depth scores increased gradually in the first, second, and third trimesters, although oral hygiene instructions were given to the entire study population. The level of statistical significance was established at P <0.05. When the clinical parameters and demographic variables were compared, only educational level and periodontal care seemed to be statistically significant (P<0.05). CONCLUSIONS: Our clinical index scores were related to the educational level of the study population. When the educational level of the study group decreased, the plaque, gingival index, and probing depth scores contrarily increased. Also non-attendance for previous periodontal care increased the scores of plaque index and probing depth. In view of the results of our study, it might be suggested that simple preventive oral hygiene programs may help maintain healthy gingiva during pregnancy.