Introduction: An important cause of morbidity and mortality of newborns all over the world is bacterial infections. One of the causative agents of invasive neonatal infections is Streptococcus Group B, which is a Gram-positive bacterium. Purpose: The purpose of the diploma work is to present current knowledge of Streptococcus Group B colonisation during pregnancy, childbirth and its influence on the child based on existing scientific and professional literature. At the same time, the purpose is to determine the consequences of infections for the newborn, including the impact of antibiotic prophylaxis on the newborn microbiome and the need to introduce a universal screening of pregnant women. Methods: A descriptive method has been used. We examined local and foreign literature in the field of maternal colonisation and neonatal infection with Streptococcus Group B. We focused mainly on colonisation during pregnancy and during labour. The existing scientific literature was searched using databases (CINAHL, PubMed, DiKUL, COBISS and Google Scholar). Results: In reviewing the literature, the author found that the most common neonatal Streptococcus Group B infections include pneumonia, meningitis and / or sepsis. The first condition for infection in the newborn is the colonisation of the mother with Streptococcus Group B. There are currently three approaches to preventing early neonatal sepsis: antibiotic prophylaxis based on risk factors, universal screening for Streptococcus Group B carriers in pregnancy and intrapartial screening. The fourth option – vaccination against Streptococcus Group B will probably not be available for clinical practice in the near future. Detection of colonised pregnant women is very important for further treatment. In pregnant women who are positive for Streptococcus Group B, the antibiotic is applied during labour. The potential disadvantage of antibiotics is that they can lead to a disbiosis of a neonate intestinal microbiom, which may lead to a greater risk of gastrointestinal and other diseases in adulthood. Discussion and conclusion: Prevention as well as early detection, diagnosis and treatment are crucial in preventing neonatal mortality and morbidity due to invasive Streptococcus Group B infections. In Slovenia, screening for Streptococcus Group B is not yet part of routine prenatal care. In the following years a national consensus on either a more stringent implementation of a risk-based approach or introduction of universal prenatal Streptococcus Group B screening will have to be reached.