 Our proposed study is designed to evaluate patients at particular risk for preterm delivery; those with advanced cervical exam. In this randomized prospective controlled study, we intend to examine the influence of adjunctive antibiotic use in preterm labor complicated by a cervical exam of 4 cm or greater. We plan to compare a study group receiving broad-spectrum antibiotics with a control group that will not receive antibiotics for pregnancy prolongation. Both groups will receive antibiotics for GBS prophylaxis as indicated. We hope to see a delay in delivery in the study group as a primary outcome. Secondary outcomes will include the use of steroids, neonatal complications including sepsis, intraventricular hemorrhage, periventricular leukomalacea, mechanical ventilation and respiratory distress syndrome, retinopathy of prematurity and necrotizing enterocolitis, and neonatal ICU stay. 