Risk-based screening and intrapartum group B streptococcus polymerase chain reactionresults reduce use of antibiotics during labour.

Introduction: This study investigated the feasibility of a risk-based screening approach combined with testing of Group B streptococcus (GBS) by polymerase chain reaction (PCR), the effect on use of intrapartum antibiotic prophylaxis (IAP) and the impact on the incidence of early-onset GBS infection (EOGBS).

Methods: During one year, 551 women giving birth at Lillebaelt Hospital, Denmark, having one or more risk factors for EOGBS (previous birth of infant with EOGBS, GBS bacteriuria during current pregnancy, gestational age less than 37 weeks, rupture of membranes greater than 18 hours, and temperature ≥ 38 °C) were tested by a GBS PCR assay intrapartum. IAP was administered when the woman tested positive.

Results: Among 2,889 women in labour, 19.1% (n = 551) had one or more risk factors for EOGBS, and 5.1% (n = 146) had both risk factors for EOGBS and a positive intrapartum GBS PCR test. In total, 185 women with risk factors for EOGBS received IAP. If the former risk-based approach had been applied, 551 women giving birth would have received IAP. Implementing IAP based on the GBS PCR results produced a two-thirds reduction of IAP. No children were diagnosed with EOGBS.

Conclusions: The GBS PCR assay was easy to perform and provided test results within 50 minutes. Implementation of risk-based screening combined with intrapartum GBS PCR testing reduces the use of IAP by two thirds compared with risk-based screening alone, thus minimising antibiotic resistance. The study material was too small to evaluate the effect on the incidence of EOGBS. Since EOGBS is a rare disease, more studies are required.

Funding: The study was supported by Forskningsraadet Lillebaelt Hospital, Udviklingsraadet Lillebaelt Hospital, Johs. M. Klein og Hustrus Mindelegat, the Region of Southern Denmark, Farusa Emballage A/S.

Trial Registration: not relevant.