Can Oral Bacteria Cause Pregnancy Complications?

ISSN 1745-5057 Women's Health (2011) 7(4), 401–404 10.2217/WHE.11. 37 © 2011 Future Medicine Ltd or the long-term care for the ones that manage to survive. As a result of the increased preterm birth rate and increased survival rate, our population of handicapped individuals has been rising steadily. Preterm births cost society more than US$26 billion annually in maternal delivery, medical care, early intervention services, special education services and loss of household and labor market productivity [3]. Clearly, prevention is the key in improving the birth outcome and the quality of life. This is only achievable when we have a thorough understanding of the cause of these complications. So far, at least half of the preterm births occur with no known causes [4]. A series of risk factors have been associated with pregnancy complications, including but not limited to: race, maternal bodyweight and age, education, socioeconomic status, prenatal care, smoking, drug abuse, past pregnancy outcome and infection [4]. Among these, infection plays one of the major roles, especially among those early preterm births, accounting for as many as three quarters of the spontaneous premature deliveries before 30 weeks [5]. The early preemies constitute the most medically relevant population owing to the high fatality rate and the longterm morbidity of the survivors. The infection could be systemic, such as respiratory infections and malaria, among others, or localized inside the womb, an otherwise sterile environment. Infections inside the intra-amniotic cavity may involve some or all of the following placental microenvironments: between uterus and fetal membranes (deciduitis), within fetal membranes (chorioamnionitis), within the placenta (villitis), within the amniotic fluid, within the umbilical cord (funisitis) or within the fetus (sepsis) [5]. It is generally accepted in obstetrical practice that in cases with proven intra-amniotic bacterial infection, the risk of maternal and neonatal sepsis outweighs the risk of prematurity and such cases are unanimously managed by a medically indicated delivery and aggressive antibiotic treatment of the mother and newborn. Thus, accurate diagnosis of microbial infection in the amniotic Intrauterine infection is a major cause of adverse pregnancy outcomes such as preterm birth and stillbirth. Accurate diagnosis of the infectious organisms and identification of the source of infection are key to patient management. The hospital laboratories still employ the traditional culturing methods, which severely limit the detection of uncultivated or microbial species that are difficult to culture. This explains at least in part some of the idiopathic adverse outcomes. In addition, the current paradigm indicates that the infectious microorganisms originate from the vaginal tract. Accumulating evidence demonstrates that oral bacteria play a significant yet previously unrecognized role in intrauterine infections. Studies in both humans and animals have demonstrated that oral bacteria can translocate to the pregnant uterus through hematogenous transmission. These recent discoveries shed new light on our understanding of pregnancy complications. Pregnancy complications, such as miscarriage, eclampsia, preeclampsia, premature delivery, low birthweight and stillbirth constitute a major public health problem. They are costly not only financially but also emotionally. According to the March of Dimes, the USA has the highest preterm birth (before 37 weeks) rate among the industrialized countries. The prematurity rate in the USA has risen steadily during the past three decades from 9.4% in 1981 to 12.8% in 2006 [1]. Although the rate has shown a slight trend of decline, dropping to 12.3% in 2008 and to 12.2% in 2009, it is still substantially higher than the goal of 7.6% set by the federal government’s Healthy People 2010 campaign [2]. With improvements in medical technology, the survival rate of the preemies has increased dramatically. However, this comes with a price. The survivors, especially the early preemies (born before 30 weeks), often suffer from complications such as cerebral palsy, learning difficulties, attention deficits and respiratory diseases, among others. The families usually carry a tremendous emotional burden owing to the loss of neonates Editorial