Miller (Dent Cosmos 1891:698–713, 1999) and Hunter (Br Med J 2:215–216, 1900) suggested the hypothesis that oral infections could spread throughout the body causing sepsis or be related to other pathologies in other systems or parts of the human body. In the 1990s, some research groups investigated possible associations between periodontal diseases and systemic diseases, such as prematurity and low birth weight. However, although there were theoretical bases related to the hypotheses tested, the experimental models indicated to explore the biological bases of this process (biological plausibility) were limited, and great part had essential limitations related to the experimental design (artificial models incompatible or not similar to the periodontal diseases which affect humans). Observational and interventional clinical studies have been developed since then, with considerable difficulties and limitations inherent in the proposal of the studies. Prematurity and low birth weight present approximately 40 associated risk factors, and periodontal diseases are multifactorial and extremely complex either. Each research carried out and published represents a new scientific contribution and the critical construction of new knowledge, the formulation of new hypotheses, and the evolution to study models closer to a definitive answer on the cause and effect relationship between periodontal diseases and adverse effects of pregnancy. Thus, the present study aims to review articles published in the last 3 years that approached this possible association. This review had a total of 14 scientific papers of the following types: observational studies, interventional studies, and experimental studies. The present study shows controversial results, with a greater number of cases of non-association between periodontal diseases and adverse pregnancy events, especially with prematurity and/or low birth weight. However, it is biologically possible that there is a relationship between diseases that affect the oral cavity and gestation in humans; more studies are necessary to have a conclusion in this regard.