Periodontal infection in women with low birth weight neonates

The association of low birth weight neonates with high health care costs and high infant mortality has been well established. It has been hypothesized that in the presence of periodontal disease, periodontal pathogens are disseminated hematogenously to target the placenta, membranes, and fetus [1], [2]. This bacterial challenge may result in increased cytokine expression, and affect placental function and precipitate preterm labor. The present case-control study was designed to investigate whether women who delivered low birth weight neonates had a higher rate of periodontal infection. A total of 150 consecutive women admitted in labor (preterm or with evidence of fetal growth restriction) with known gestational age and a first trimester ultrasound dating scan were recruited to the case group. Informed consent was given by all participants. The control group consisted of women who had delivered a neonate of appropriate size for gestational age at term (≥ 37–41 weeks), matched to each case participant for age, parity, and socioeconomic status. Oral examinations were carried out within 72 hours of delivery by a periodontist blinded to the case-control status. Periodontal infection was considered positive if any of the following were present: poor oral hygiene index (simplified), gingival index of > 1 (moderate to severe gingivitis), or periodontal pocket depth of ≥ 4 mm. Periodontal infection was noted in 59% (177/300) of women in the study. The presence of periodontal infection was significantly higher in women with preterm (92.1%; 82/89 cases) and growth restricted neonates (91.8%; 56/61 cases) compared with women in the control group (26%; 39/150 cases) (P < 0.001). All clinical parameters considered to indicate periodontal infection showed a significant association with low birth weight neonates. These parameters, whether used individually or inferred together, were indicative of periodontal infection and correlated with pregnancy outcomes. Multiple risk factors for low birth weight neonates are recognized. Environmental, occupational, and personal characteristics or comorbidities (whether pregnancy-specific or otherwise) could all contribute singly or in combination to delivery of a low birth weight neonate. Therefore, the preponderance of periodontal disease in these women cannot be considered as the cause of low birth weight neonates unless these variables are controlled for. Irrespective of the variables we studied (age group, parity, past obstetric performance, socioeconomic status, educational level, occupation, prenatal care, body mass index, hemoglobin estimate, and pregnancy specific hypertension) the presence of periodontal infection was found to be significantly higher in women who delivered low birth weight neonates compared with the control group (Fig. 1). Proportion of periodontal infection (PDI) and confounding variables for low birth weight neonates. Although some authors have not found an association with mild periodontal disease [3], it has been suggested that periodontal treatment may reduce the risk for low birth weight neonates [4]. The findings that periodontal infection is prevalent in pregnancy and significantly higher in women who delivered low birth weight neonates suggest a need for developing preventive strategies. The clinical diagnosis of periodontal infection correlated with either inflammatory mediators or microbiological confirmation would add validity to the claims of a causal relationship.