Data collection: Demographic information such as age, race, date of initial GBS culture and time of rupture of membranes will be abstracted from enrolled patients' charts. Intrapartum vaginal cultures will be collected with a vaginal swab from the distal vagina by trained obstetrics and gynecology residents, attendings, nurses, nurse midwives and nurse practitioners prior to the initiation of antibiotics and at two hour intervals until delivery or after eight hours has elapsed.