Reduction of intrapartum antibiotic prophylaxis by combining risk factor assessment with a rapid bedside intrapartum polymerase chain reaction testing for group B streptococci.

OBJECTIVE

To investigate the impact of administering Intrapartum Antibiotic Prophylaxis (IAP) to laboring women with one or more risk factors for Early Onset Group B Streptococcal neonatal infection (EOGBS) based on the result of a rapid bedside test for Group B Streptococci (GBS).

STUDY

DESIGN

Quality assessment study.

METHODS

Three-hundred-sixty-six laboring women admitted to our maternity ward, with one or more risk factors for EOGBS, were prospectively included. Rectovaginal swab-samples were examined bedside by the GenomEra® GBS Polymerase Chain Reaction (PCR) assay upon admission. Time from administration of IAP to delivery was registered. According to national guidelines, one-hundred-two women mandatorily received IAP independent of the PCR test result fulfilling one of the following three risk factors: prior infant with EOGBS, preterm labor before 35 gestational week, temperature ≥ 38 °C during labor. Women with GBS bacteriuria during current pregnancy, rupture of membranes ≥ 18 h IAP, and preterm labor between 35 and 37 gestational week, received IAP solely if the PCR test was positive. Predictive values were calculated for each risk factor.

RESULTS

Previous GBS bacteriuria was strongly associated (PPV = 71%) with a positive GBS PCR test, whilst the corresponding positive percent of ROM > 18 h and of GA 35-37 was only PPV = 16% and 22%, respectively. Seventy-four women, 74/251 (31%), received IAP because they were GBS PCR positive. IAP was thus reduced by about two-thirds compared to the risk-based strategy of offering IAP to all women with one or more risk factors for EOGBS. Two women, 2/254 (0.8%), received inferior care, as they did not receive IAP within the recommended 4 h prior to delivery due to the extra time spend on the test procedure.

CONCLUSION

Bedside intrapartum PCR testing of women with risk factors for EOGBS effectively diminishes use of IAP during labor compared to the present risk factor-based strategy alone. In this project, the extra time spend on the PCR test procedure did not lead to noticeable delay in IAP.