We investigated if clinicians were altering their care of group B streptococcus (GBS)-positive women in labor to achieve 4 hours of intrapartum antibiotic prophylaxis based on their interpretation of the 2002 Centers for Disease Control (CDC) guidelines on prevention of perinatal GBS disease. Methods. Two study groups: women who correctly underwent the CDC 2002 guidelines (study group 1) and women who did not (study group 2). Intrapartum chemoprophylaxis (IC) was administered to all pregnant women identified as GBS carrier. Group B streptococcus (GBS) remains a leading cause of serious neonatal infection despite great progress in perinatal GBS disease prevention in the 1990s. In 1996, CDC, in collaboration with other agencies, published guidelines for the prevention of perinatal group B streptococcal disease (CDC. Group B streptococcal (GBS) disease remains the leading cause of early-onset neonatal sepsis in the US. In collaboration with professional organizations, CDC provides an algorithm for intrapartum prophylaxis, if appropriate, for women in labor. Based upon this evidence, the Centers for Disease Control and Prevention (CDC) published updated guidelines for prevention of neonatal GBS disease in 2002 and 2010 . The key intervention of these guidelines is intrapartum parenteral antibiotic prophylaxis of women whose infants are at risk of developing early-onset GBS infection because a Prevention of Perinatal Group B Streptococcal (GBS) Disease . BACKGROUND: indication for GBS prophylaxis exists for current pregnancy) prolong the latency of the pregnancy. CDC guidelines do not address the use of antibiotics to prolong This video commentary from the CDC highlights the key changes to the new 2010 guidelines for preventing group B strep disease in the neonate. the 2002 guidelines: Pregnant women should undergo delivery of an infant with invasive GBS disease and GBS bacteriuria during the current pregnancy. Furthermore, GBS also cause 15-25 % of the