Background: Intrapartum administration of cefazolin, a first-generation cephalosporin, is used to prevent vertical transmission of Group B Streptococcus (GBS) in mothers allergic to penicillin without a history of anaphylaxis. Early onset sepsis in the new-born following transmission of GBS during labor or birth may be prevented when exposure to unbound cefazolin in the neonate serum […]