Methods: Three hundred and seventy-two subgingival plaque samples were obtained from pregnant women attending an ante-natal clinic in Mitchells Plain. Plaque Index, Gingival Index, Pocket Depth and Loss of attachment were recorded as well as stage of gestation. Plaque samples were analyzed by the enzymatic BANA test for detection of members of the "red complex" accoding to the Perioscan manufacturer's instructions. Samples were recorded as positive if the test turned blue and negative if there was no colour change.
Results: The BANA test was positive in 25.75% of the subjects examined. Multiple regression analysis showed that there was a positive association of BANA-positive samples with clinical indices.
Conclusion: This study confirms the sensitivity of BANA in detecting the anerobic Gram-negative bacteria which constitute the "red complex" and suggests its use as an indicator for pregnant women at risk for pre-term delivery.