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A Murine Model of Group B Streptococcus Vaginal Colonization
10:19

A Murine Model of Group B Streptococcus Vaginal Colonization

Published on: November 16, 2016

Benzylpenicillin Concentrations in Intrapartum Group B Streptococcus Prevention Guidelines; A Systematic Review of

Brian Deegan1, Ashley Gourlay1, Lars Eriksson2

  • 1Women's and Newborn Services, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia.

The Australian & New Zealand Journal of Obstetrics & Gynaecology
|July 1, 2026
PubMed

Insights

Intrapartum antibiotics like benzylpenicillin are used to prevent Group B Streptococcus (GBS) disease. Current evidence is insufficient to confirm if fetal drug concentrations meet the minimum inhibitory concentration (MIC) for GBS.

Area of Science:

  • Obstetrics and Gynecology
  • Neonatal Medicine
  • Pharmacology

Background:

  • Intrapartum antibiotics are administered to reduce neonatal risk of early-onset Group B Streptococcus (GBS) disease.
  • Protocols aim to achieve fetal serum and amniotic fluid concentrations above the GBS minimum inhibitory concentration (MIC) at birth.

Purpose of the Study:

  • To summarize evidence on intrapartum benzylpenicillin dosing.
  • To compare fetal serum and amniotic fluid concentrations with GBS MICs.

Main Methods:

  • Systematic review of PubMed, CINAHL, Cochrane Library, and Embase.
  • Included studies examining benzylpenicillin concentrations in umbilical cord blood and/or amniotic fluid.

Main Results:

  • Seven studies were included with varied doses and methods.
  • Benzylpenicillin concentrations were often higher than the target MIC (0.125 mcg/mL).
  • Methodological limitations included reporting total concentrations and protocol violations.

Conclusions:

  • Lack of high-quality evidence supports current intrapartum antibiotic dosing for achieving adequate fetal MICs.
  • Rigorous studies accounting for drug protein binding are needed to optimize dosing regimens.
Abstract

Keywords:
benzylpenicillinfetal bloodgroup B Streptococcusneonatalsystematic review

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