Pregnant women are particularly prone to periodontal (gum) disease as they go through the hormonal changes associated with pregnancy, and research has found that women with periodontal disease may be at higher risk of delivering pre-term low birthweight (PLBW) infants.

Researchers have studied the relationship between infection and PLBW, particularly genitourinary tract infection (GUI), for several years. It appears GUI infection causes the levels of PGE2 (prostaglandin), and TNFa (tumor necrosis factor), biological fluids that normally induce labor, to increase rapidly, leading to premature delivery. Scientists suspect periodontal disease, also a bacterial infection, could trigger a similar increase in PGE2 and TNFa molecule levels, thus inducing premature labor.

The relationship between infection, especially GUI, and adverse pregnancy outcomes has been well-documented in animals; and human studies. In a recent study of periodontal infection in pregnant or postpartum women, those with periodontal disease were more likely to deliver a PLBW infant than women without periodontal disease. Medical professionals have been intrigued by these results and have urged additional research in this area.

PLBW babies, infants born before the 37th week of pregnancy, account for 5 million neonatal intensive care unit days a year, at an annual cost of more than $5 billion. Additionally, 25 percent of PLBW births occur without a known risk factor such as tobacco use, genetics, drug and alcohol use, level of prenatal care, nutrition and urinary tract infection. The extent to which periodontal disease contributes to the unexplained risk of PLBW births is important to know, and several studies are ongoing to assess this association.