The goal of this study is to help identify the best antibiotic treatment for pregnant people when their water breaks prematurely (a condition abbreviated as PPROM). Current practice is to attempt to maintain the pregnancy until at least 34 weeks gestational age, when the risks of prematurity to the baby are lessened. Research shows that antibiotics help the pregnancy last longer, but there have been limited studies about which combination works best. Currently, both azithromycin and erythromycin are accepted antibiotic treatments, in addition to ampicillin and amoxicillin. Participants diagnosed with PPROM will be randomized to receive ampicillin and amoxicillin plus either azithromycin or erythromycin, in addition to the care they would normally receive. Studying these two drugs will help decide the best care for future patients with PPROM.

Preterm pre-labor rupture of membranes (PPROM) complicates 3% of pregnancies and accounts for one-fourth to one-third of preterm births. PPROM is associated with significant maternal and neonatal morbidities, including chorioamnionitis, endometritis, neonatal sepsis, prematurity-related pathologies. In the absence of labor or indication for immediate delivery, patients who present at less than 34 weeks gestational age are treated with antibiotics to prolong pregnancy until 34 weeks when the risks of prematurity are decreased. Based on randomized trials, both the American College of Obstetrics and Gynecology (ACOG) and the Society of Maternal Fetal Medicine (SMFM) recommend IV ampicillin and IV erythromycin for 2 days, followed by an oral regimen of amoxicillin and erythromycin for 5 days. Due to the recent limited availability of erythromycin, azithromycin has been used a substitute. There have been observational studies showing no difference in duration of pregnancy between azithromycin and erythromycin, however no randomized controlled trial has been carried out to our knowledge. This study performs a cluster randomized controlled trial to examine the efficacy of azithromycin versus erythromycin as a component of the "latency antibiotics" used to prolong pregnancy in PPROM patients.

Inclusion Criteria:

• Pregnancy at 22 weeks 0 days to 32 weeks 6 days of gestation.
• Rupture of membranes confirmed by biochemical testing.
• Membrane rupture within the past 36 hours.
• Cervical dilation 3 cm or less and 4 or fewer contractions within 60-minutes at the time of admission.
• Age ≥18 and <50 years.

Exclusion Criteria:

• Non-reassuring fetal heart tracing, vaginal bleeding, chorioamnionitis or any indication for delivery at admission.
• Allergy to penicillin, erythromycin, or azithromycin.
• Multiple gestations.