Latency Antibiotics for Previable Rupture Of Membranes Trial

Inclusion Criteria: * Preterm premature rupture of membranes at less than 22 weeks. * Membrane rupture had occurred within 36 hours of randomization. * Cervical dilatation is 3 cm or less (on visual or clinical examination). * 4 or fewer contractions in the 60-minute monitoring period before randomization. * Singleton gestation. Twin gestation reduced to singleton, either spontaneously or therapeutically, is not eligible unless the reduction occurred before 14 weeks project gestational age * Gestational age at randomization less than 22 weeks (≤21 weeks and 6 days) based on clinical information. Exclusion Criteria: * Nonreasoning fetal testing * Vaginal bleeding * Maternal or fetal indication for immediate delivery * Cervical cerclage in place * Receipt of latency antibiotics prior to randomization (azithromycin, ampicillin, or amoxicillin) * Allergy to Penicillins or Azithromycin * Febrile illness requiring antibiotics * Placenta previa * Multifetal gestation