Purpose: To determine the effects of sociodemographic and pregnancy-related factors on oral health attitudes during pregnancy, as well as the main predictors of proper oral practices. Materials and Methods: An electronic survey consisting of 47 (single or multiple-choice) questions was conducted in women up to 3 years after childbirth in 2017. Sociodemographic data, as well as information on the course of pregnancy and delivery, oral knowledge and basic behaviours during pregnancy were collected. The Chi-square test and Spearman's rank correlation coefficient were used for statistical analysis. Odds ratios were determined. A statistical significance level of 0.05 was used. Results: A total of 2480 questionnaires completed by women aged between 13 and 45 years who were up to 3 years after delivery, were analysed. Correct answers to all questions regarding basic oral health and oral practices were obtained by 20.8% and 19.6% of respondents, respectively. Proper health behaviours were more strongly correlated with the level of knowledge (r = 0.155; odds ratio (OR) = 2.44; CI:1.93–3.07; p <0.001) and the use of dental care before pregnancy (r = 0.187; OR = 2.88; CI:2.29–3.63; p <0.001) rather than age (r = 0.144), good or very good financial status (r = 0.110), high level of education (r = 0.081), urban residence (r = 0.058) or occupational activity (r = 0.049). Attending dental visits depended on the conviction about their safety (r = 0.195; OR = 2.47; CI: 2.09–2.93; p <0.001) as well as gynaecologist's referral in the case of general conditions in pregnancy (r = 0.052) and the risk of premature birth (r = 0.053). No effects of other parameters associated with pregnancy or delivery were confirmed. Conclusion: Health attitudes during pregnancy are modified by sociodemographic factors. The main predictors of proper health behaviours include high level of knowledge on oral health and the use of dental care before conception. Furthermore, dental attendance among pregnant women depends on the awareness of the safety of dental visits and a gynaecologist referral in case of general condition and risk of premature birth.