: Periodontitis is today considered to be a serious disease of periodontal tissues, one caused in most cases by bacterial infection which stimulates proteolysis and osteolysis of the tissues. Typical for the disease is formation of periodontal pockets and a chronic destructive inflammation which impacts on the whole organism. Periodontopathic bacteria colonized in a subgingival biofilm cannot be removed by common oral hygiene. Overproduction of bacteria and other pro-inflammatory mediators can increase the total pro-inflammatory state of the organism in pregnant women. Increased levels of some pro-inflammatory cytokines (PGE2) and cells in fetoplacental space can lead to premature rupture of membranes and subsequent delivery of immature babies. An increasing number of studies in this field provide evidence that good professional care and personal oral hygiene can bring benefits through a decreased prevalence of preterm low birth weight infants (PLBWI) in women suffering periodontitis, although definitive conclusions have not yet been reached. Future mothers with periodontitis can run not only an increased risk of PLWBI but often also suffer pre-eclampsia - a state called acute atherosis - which can be ethiopathogenetically associated with high concentrations of various pro-inflammatory mediators. An increased production of female hormones during pregnancy contributes to the development of gingivitis and periodontitis because vascular permeability and possible tissue edema are both increased.