Method: this is a prospective cohort of pregnant women. Participants were 24 pregnant women who underwent dental examination, collection of blood and saliva in the first and last trimester of pregnancy and postpartum. The presence of caries was evaluated by the criterion recommended by Nyvad, considering the number of new active lesions occurred between early pregnancy and the postpartum period. Additionally it was evaluated socioeconomic conditions, dietary and dental hygiene. Spearman correlation test was used to analyze correlations between the levels of Ca and P in blood and saliva. Associations were estimated by incidence ratio risk (IRR) in multivariate Poisson regression analysis (alpha=5%),
Result: there were strong positive correlations between levels of salivary Ca and serum P, between serum Ca and PTH and between serum P and vitamin D during pregnancy, besides correlation between the level of serum P in pregnancy and postpartum salivary Ca. Higher incidence of dental caries was seen in woman with high levels of Ca in saliva (IRR=1,88; 95%CI: 0,12-29,67) and blood (IRR=4,89; 95%CI: 0,04-1,85) during pregnancy and postpartum, as well as among pregnant women that had low levels of P in saliva (IRR=0,66; 95%CI: 0,22-2,00) and blood (IRR=0,77; 95%CI: 0,01-78,5), however, both crude and adjusted associations were not statistically significant,
Conclusion: changes in Ca and P salivary and serum during pregnancy are not related to the increased incidence of caries. The higher incidence of caries in pregnant women is probably related to extrinsic changes.