In 1900, William Hunter, a British physician, first developed the idea that oral microorganisms were responsible for a wide range of systemic condition and he also identified gingivitis and periodontitis as foci of infection. The focal infection theory, proposed by hunter was based on almost no evidence. Currently, in re-examining the potential association between oral infections and systemic conditions, it is important to determine what evidence is available, and is still needed to substantiate the association and to validate the possible mechanism of association. So this evidence paper reviews current knowledge relating periodontitis to preeclampsia and pre term birth(PTB).Thus the Focused question: is “does periodontitis cause adverse pregnancy outcomes?'’ BACKGROUND: Periodontitis is an inflammatory disease affecting supportive tissues of the teeth, leading to progressive destruction of connective tissue attachment and the alveolar bone. This destruction is characterized by the formation of a periodontal pocket. Because of its chronic inflammatory infectious nature, periodontitis has been considered a systemic exposure implicated with causative agent in variety of systemic diseases and condition. Recent findings have suggested that periodontal diseases are associated with a higher risk of cardiovascular diseases, atherosclerosis and adverse pregnancy outcomes, such as preterm birth and low birth weight and preeclampsia.