Group B streptococcus infection and pregnancy

Sifakis S1, Kappou D1, Botsis D2

1Department of Obstetrics and Gynecology, University of Crete, Herakleio, Greece
22nd Department of Obstetrics and Gynecology, University of Athens, Aretaieio hspital, Athens, Greece

Correspondence: Sifakis Stavros, 228 Oulaf Palme St, GR-71410, Herakleio, Crete, Greece. E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.




Group B streptococcus (GBS) consists a leading cause of neonatal mortality and morbidity, because it is the most frequent cause of neonatal sepsis and meningitis in the developed countries. GBS infection in infants is classified into early-onset disease, which occurs within the first week of life, and late-onset disease. GBS colonization of the genital and lower gastrointestinal tracts is observed in 6.5% to 45% of pregnant women (usually without any obvious symptoms) in the United States and Europe, and is considered the main predisposing factor for early onset GBS disease in the neonates. Fifty percent of the babies who are vaginally delivered from carrier mothers will become colonized, and 1-2% of those infants will develop an active GBS disease, which is characterized by a wide spectrum of clinical manifestations. Current protocols for the prevention of neonatal GBS disease recommend the use of intrapartum antibiotic prophylaxis into those women who are indicated by the presence of risk factors or in those women with a positive culture for GBS carried out antenatally. Lately, the guidelines in the United States include the universal screening of all pregnant women at 35 to 37 weeks of gestation for vaginal and rectal GBS colonization and the use of penicillin-G (or ampicillin) in all GBS carriers who are expected to deliver vaginally. Despite the remarkable decrease of the affected cases as well as the increase in the survival rate, the neonatal GBS disease remains a significant cause of mortality and morbidity, particularly among preterm infants. Moreover, the antenatal treatment aiming at the elimination of the GBS colonization of the female genital tract has been proved ineffective. In the future, the development of a vaccine and its universal use may effectively contribute to the prevention of neonatal GBS disease and will reduce both the cost and the adverse effects of the wide use of antibiotics. This review summarizes current knowledge regarding epidemiology, laboratory diagnosis, clinical manifestations, screening strategies, identification of carriers, and management of neonatal GBS disease.

Key words: group B streptococcus; neonatal infection; pregnancy; penicillin; intrapartum antibiotic prophylaxis