Pre-term low birth weight may be associated with increased levels of Bacteroides forsythus in subgingival plaque

Subjects. The authors studied 213 pregnant or postpartum young women, ages 12 to 19 years (mean age, 16.7 ± 1.4), who were consecutively e nrolled from the School for Pregnant and Parenting Teens in central Harlem, New York, NY; 60% of them were African American and 39% were Hispanic. Exposure. The primary exposure was whether the subjects enrolled in the study during pregnancy or postpartum; this exposure was a surrogate for periodontal treatment during pregnancy, because all subjects received periodontal treatment after enrollment. The subjects were exposed to a single session of treatment including oral hygiene instruction, full mouth debridement with hand or ultrasonic instruments, polishing with a fluoridated paste, and dental sealants as needed. The 107 subjects enrolled during pregnancy received the treatment before delivery, predominantly in the second trimester (considered exposed), and the 106 enrolled postpartum received the treatment within 3 months after delivery (considered unexposed). Other exposures included plaque index, percentage of sites with bleeding on probing, percentage of sites with calculus, probing depth (mm), and average microbial load for specific bacteria between mothers of healthy and pre-term low birth weight babies. Main Outcome Measure. The incidence of pre-term delivery or delivery of low-birth weight infants in either group. Main Results. Significantly elevated levels of the gram-negative anaerobes, Bacteroides forsythus and Campylobacter rectus, were observed in subgingival plaque samples of the subjects enrolled postpartum who delivered PLBW infants, compared with those enrolled postpartum who delivered healthy infants. The administration of periodontal treatment to pregnant subjects before delivery had no significant effect on the incidence of PLBW infants (10 PLBW cases out of 74 [13.5%] for those receiving treatment versus 17 PLBW cases out of 90 [18.9%] not receiving treatment).