Maternal BANA Test Status and Preterm Labor

Objective: To address the link between periodontal pathogens measured with the BANA test (N-benzoyl-DL-arginine-2-naphthylamide) and preterm birth (PB) (<37th week gestation).

Methods: A prospective study was performed in Changhua, Taiwan. Periodontal examination included plaque score, gingival bleeding score and measurement of BANA enzyme in plaque samples at the second and third trimester. Independent variables including maternal demographics (age, occupational and educational level, ethnicity, and medical history), risk factors for PB (pre-pregnancy BMI, smoking, alcohol drinking), previous pregnancy outcome (number of previous pregnancies, previous preterm, low birth weight and abortion history), current pregnancy status (genitourinary infection, time of first pre-natal visit, frequency of prenatal visit), and dental history were investigated. Pregnancy outcome data were collected, including gestational age, birth weight at delivery, and complications during pregnancy.

Results: Subjects (n=299) with pregnancy outcome and BANA test results were available for data analysis. There were 19(7%) PB deliveries. Fisher's exact test revealed that categorical variables of previous PB history, previous LBW, pre-contraction, antepartum hemorrhage(AH), placenta previa(PP) and preterm premature rupture of membrane(PPROM) were significantly related to PB(p=0.044, 0.034, 0.013, <0.001, <0.001 and <0.001 respectively). Maternal weight gain (WG) showed a significantly difference between PB and normal term (p=0.001). These explanatory variables as well as BANA infected sites in the third trimester (BANA) and ethnicity were evaluated as predictor variables in a logistic regression model. Only BANA(Odds ratio(OR)= 5.786, 95% CI=1.198 to 27.950), WG(OR=0.793, 95%CI= 0.656 to 0.959), pre-contraction(OR=3.793, 95%CI=1.012 to 14.211), PP(OR=88.163, 95%CI=1.668 to 4658.869), PPROM(OR=22.674, 95%CI=5.826 to 88.247) were shown to have a significant influence on the PB outcome.

Conclusion: BANA-positive plaques were associated with PB, after controlling for other risk factors.