Introduction Periodontal diseases are widespread in women of reproductive potential. Although their treatment of these disorders contributes to oral health, there is still no conclusive evidence that this intervention has a beneficial effect on the course of pregnancy, in particular the rate of premature births. On the one hand, the aim of the paper is a systematic assessment of the association between periodontal diseases and pregnancy complications, based on the current literature. On the other hand, the efficacy of periodontal treatments vs. no treatment in pregnant women should be assessed with the target criterion of premature birth or other pregnancy complications. Materials and methods The narrative review was based on the PRISMA statement. Premature births were defined as primary endpoints, while various perinatal and maternal outcomes were grouped together as secondary endpoints. An electronic database search for relevant meta-analyses and systematic reviews was carried out in PubMed and the Cochrane database. Methodological characteristics and the results of the included studies were extracted. The RR or OR (95% CI) was used to measure the result. The quality of the included studies was assessed according to the AMSTAR checklist. Results Seven publications were included (total number of subjects n = 56755). The majority of included studies do not demonstrate a significant association of periodontal disease and/or periodontal treatment with certain childhood and/or maternal outcomes. The quality of the included studies was deemed to be sufficient. Conclusion Even today, there is insufficient evidence to confirm the correlation between periodontal disease and certain maternal and/or infantile outcomes. Periodontal treatment during pregnancy also does not seem to affect the risks of pregnancy. Nevertheless, it is recommended that all pregnant women are advised to improve their daily oral hygiene in order to prevent inflammatory diseases, regardless of the progress of the pregnancy.