Rationale. Gingivitis and periodontitis represent highly prevalent oral pathologies in pregnant women. The physiological, immunological and endocrine changes imposed by pregnancy are associated with a greater predisposition for the development of gingivitis. Considering the potential association between the presence of gingivitis and the development of complications during pregnancy and the time of delivery (preeclampsia, preterm, IUGRs), it is important to evaluate the impact of early administration of a mixture of lactobacillus on improved health oral status, and at the same time assessing the effect on risk reduction of prematurity and/or IUGRs.