Urine dipstick for predicting intrapartum recto-vaginal colonisation by group B streptococci

Introduction: In pregnant women, bacteriuria with group B streptococci (GBS) may be associated with a high degree of recto-vaginal GBS colonisation and therefore an increased risk of early-onset GBS disease. The aim of this study was to assess the performance of routine use of dipstick urine analysis during pregnancy for prediction of recto-vaginal GBS colonisation at the time of labour. Methods: Among 902 unselected Danish pregnant women, we obtained results from 1) dipstick urine analysis, 2) urine culture carried out during pregnancy, if indicated, and 3) recto-vaginal culture at labour. The inclusion criteria were age > 18 years and gestational age ≥ 37 weeks. Results: Intrapartum recto-vaginal GBS colonisation was predicted by a positive urine dipstick with 5% sensitivity only. Conclusion: Dipstick urine analysis had a low sensitivity for predicting intrapartum recto-vaginal colonisation with GBS.