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Preventing Early-Onset Group B Streptococcus neonatal infection and reducing antibiotic exposure using a rapid PCR
Mandy Wang1,2, Caitlin Keighley2,3, Matthew Watts2,3
1Department of Women's and Newborn Health, Westmead Hospital, Sydney, New South Wales, Australia.
Insights
A hybrid approach combining risk factors and GBS PCR screening effectively prevents early-onset Group B Streptococcus (EOGBS) infections in newborns while minimizing antibiotic exposure for mothers and babies.
Area of Science:
- Obstetrics and Gynecology
- Neonatal Infectious Diseases
- Microbiology
Background:
- Optimizing intrapartum antibiotic prophylaxis (IAP) to reduce early-onset Group B Streptococcus (EOGBS) neonatal infections and antibiotic exposure is challenging.
- Current strategies include routine screening or risk-factor-based approaches, with uncertainty regarding the best method.
Purpose of the Study:
- To evaluate a hybrid risk-and-screen approach for EOGBS prevention in women with term prelabour rupture of membranes (TermPROM).
- To assess the effectiveness of using GBS polymerase chain reaction (PCR) testing in a hybrid strategy.
Main Methods:
- Retrospective cohort study of women with TermPROM.
- Non-labouring TermPROM women underwent rapid GBS PCR testing; positive results led to induction and IAP.
- GBS screen-negative women were managed expectantly without IAP unless other risk factors emerged.
Main Results:
- A low rate of culture-positive EOGBS (0.36/1000 live births) was observed from 2009-2018.
- Over 1100 women with prolonged rupture of membranes (≥18 hours) avoided antibiotics due to negative GBS PCR results.
- No EOGBS cases occurred in TermPROM women or due to protocol failures.
Conclusions:
- A hybrid approach integrating risk factors and GBS PCR screening for TermPROM women achieves low EOGBS rates.
- This strategy effectively minimizes and targets antibiotic use in obstetric care.
Background:
How best to target intrapartum antibiotic prophylaxis (IAP) to minimise both Early-Onset Group B Streptococcus (EOGBS) neonatal infection and maternal/fetal antibiotic exposure is uncertain, with both routine-screening and risk-factor approaches available.
Aims:
This retrospective cohort study was undertaken to examine the outcomes of a hybrid risk-and-screen approach to EOGBS prevention using GBS polymerase chain reaction (PCR). The target population was women with term prelabour rupture of membranes (TermPROM) having the risk factor of prolonged rupture of membranes (ROM) ≥18 h.
Materials And Methods:
Non-labouring TermPROM women had rapid GBS PCR testing at presentation. GBS screen-positive women proceeded to induction of labour and received IAP. GBS screen-negative women were allowed home to await spontaneous labour and not given IAP regardless of duration of ROM, unless other risk factors developed. For all other women, the risk-factor approach was followed.
Results:
From 2009 to 2018, there were 20 cases of culture-positive EOGBS, a rate of 0.36/1000 live births (95% CI 0.22-0.56/1000), comparable to other recent reports. Over 2010-2018 when laboratory data were available, 1120 TermPROM women with ROM ≥18 h avoided antibiotics because they were GBS PCR-negative (2.3% of all births, 3.6% of vaginal births) while 338 TermPROM women with ROM <18 h received targeted antibiotics for being GBS-positive. No cases of EOGBS occurred in TermPROM women, those with ROM ≥18 h, or due to protocol-compliance failure.
Conclusions:
A hybrid approach involving risk-factor-based IAP and intrapartum GBS PCR screening of non-labouring TermPROM women delivers acceptably low rates of EOGBS while minimising and better targeting antibiotic exposure.
