Periodontal disease leads to adverse pregnancy outcomes according to a recent study published in the Periodontology 2000
Periodontal health in pregnant women has become a field of research since the 1960s, resulting in a flurry of studies to focus on it. Gingival inflammation associated with pregnancy has been initiated by dental plaque and exacerbated by endogenous steroid hormones. Meanwhile, the bidirectional interaction between systemic conditions and periodontal status has been taken more seriously into consideration with the proposition of periodontal medicine since the middle 1990s. Although it is mandatory to exclude the effects of previously existing periodontal inflammation and dental plaque in order to explore the sole effect of pregnancy on periodontal health, the works of research in this regard have rarely been performed.

An increase in the prevalence and severity of gingival inflammation during pregnancy has been reported since the 1960s. Though the aetiology is not fully known, it is believed that increasing plasma sex steroid hormone levels during pregnancy have a dramatic effect on the periodontium. Current works of research have shown that estrogen and progesterone increase during pregnancy are supposed to be responsible for gingivitis progression. Women are particularly susceptible to developing gingival problems during pregnancy. In addition, periodontal disease in pregnant women may lead to adverse outcomes for both mother and infant, which have serious clinical and public health implications.
Both scenarios have been extensively researched, helping to bring attention to pregnant women as an important and vulnerable population as it concerns periodontal health. The increase in gingival inflammation caused by hormonal changes in pregnant women is undisputed and has been studied and documented since the 1960s, although the exact aetiology is not fully understood. The relationship between periodontal disease during pregnancy and adverse pregnancy outcomes is less substantiated, because of conflicting evidence.
This review of the biomedical and epidemiologic literature provides an overview of both sides of this relationship and examines the potential mechanisms for developing periodontal disease during pregnancy and the proposed mechanisms by which periodontal disease leads to adverse pregnancy outcomes.
Reference:
Periodontology and pregnancy: An overview of biomedical and epidemiological evidence by Karen Raju, et al. published in the Periodontology 2000
https://doi.org/10.1111/prd.12394