Preterm Premature Rupture of Membranes (PPROM) is treated with an antibiotic, erythromycin or azithromycin, to prolong pregnancy. Erythromycin is taken for several days and can result in stomach upset in some patients, causing them to stop taking the medication. Therefore, azithromycin is often prescribed instead. Azithromycin is usually taken only once and stomach upset is not seen or greatly reduced. The goal of this study is to see if there is a difference between the antibiotic (azithromycin) compared to the antibiotic (erythromycin) in prolonging pregnancy in patients with Preterm Premature Rupture of Membranes (PPROM). The working hypothesis is that there is no difference in the clinical effectiveness between antibiotic regimens containing te macrolides azithromycin and erythromycin for prolonging latency in PPROM.

The current standard regimen for PPROM patients between the gestational age of 24 0/7 and 32 0/7 weeks, is to administer ampicillin 2gm IV every 6hours for 48hrs followed by amoxicillin 250mg orally every 8 hours for 5 days, with erythromycin 250mg IV for 48hours followed by 500mg orally every 8hours for 5 days. Our study design would be a prospective randomized trial. Consented, eligible women will be randomized to receive ampicillin as above plus either azithromycin 1 gm orally at enrollment or erythromycin 250mg IV every 6 hours for 48hours followed by 500mg orally every 8hours for 5 days. Those who are unable to tolerate the 1gm of azithromycin within the first 30 minutes of administration, a 1000mg powder suspension will be given. In conjunction with standard protocol, a course of steroids for fetal lung maturity will be administered upon the treating staff's discretion, and all Group B Beta Streptococcus positive patients will be treated.

Inclusion Criteria:

• Pregnant women at least 18 years old
• Gestational age of 24 0/7 to 32 0/7 weeks
• Singleton gestation
• Randomization within 36 hours of rupture of membranes.
• Cervical dilation less than or equal to 4 cm.

Exclusion Criteria:

• Known lethal fetal anomaly
• Vaginal bleeding
• Maternal or fetal indication for delivery
• Diagnosis of chorioamnionitis on admission
• Cervical cerclage in place
• Placenta previa or other known placental anomalies
• Use of antibiotic therapy within 5 days.
• Allergy or other contraindications to erythromycin/azithromycin or steroid use.

Pregnant women with the diagnosis of PPROM will be enrolled in this protocol.