BACKGROUND: Group B streptococcal infection is common in pregnant women without causing harm. However it is also a significant cause of neonatal morbidity and mortality.

OBJECTIVES: The objective of this review was to assess the effects of intrapartum administration of antibiotics to women on infant colonization with group B streptococcus, early onset neonatal group B streptococcus sepsis and neonatal death from infection.

SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register was searched.

SELECTION CRITERIA: Controlled trials of pregnant women colonized with group B streptococcus comparing intrapartum antibiotic administration with no treatment, and providing data on infant colonization with group B streptococcus and/or neonatal infection.

DATA COLLECTION AND ANALYSIS: Eligibility and trial quality assessment were done by one reviewer.

MAIN RESULTS: Five trials were included. Overall quality was poor, with potential selection bias in all the identified studies. Intrapartum antibiotic treatment reduced the rate of infant colonization (odds ratio 0.10, 95% confidence interval 0.07 to 0.14) and early onset neonatal infection with group B streptococcus (odds ratio 0.17, 95% confidence interval 0.07 to 0.39). A difference in neonatal mortality was not seen (odds ratio 0.12, 95% confidence interval 0.01 to 2.00).

AUTHORS' CONCLUSIONS: Intrapartum antibiotic treatment of women colonized with group B streptococcus appears to reduce neonatal infection. Effective strategies to detect maternal colonization with group B streptococcus and better data on maternal risk factors for neonatal group B streptococcus infection in different populations are required.