Group B streptococcus is commonly found in the human body and in 10-35% of health women. Group B streptococcus does not usually cause any symptoms for adults but for infants it can be deadly. Group B streptococcus can be transmitted from mother to child during childbirth. Typically your gynecologist will test for Group B streptococcus during your pregnancy. If it is found an antibiotic is used during labor to minimize the risk of passing Group B strep to your infant.