title: A retrospective comparison of antibiotic regimens for preterm premature rupture of membranes.
abstract: OBJECTIVE
  To evaluate whether the use of ampicillin and azithromycin leads to a similar latency period in preterm premature rupture of membranes as ampicillin and erythromycin and whether the substitution of azithromycin for erythromycin effects rates of other outcomes.
  
  
  METHODS
  We performed a retrospective cohort study of women with preterm premature rupture of membranes between 24 and 34 completed weeks of gestation and compared two groups: those who received ampicillin and erythromycin and those who received ampicillin and azithromycin. Primary outcome was length of latency (defined as time from first antibiotic dose to delivery) and secondary outcomes were rates of chorioamnionitis, cesarean delivery, Apgar scores, birth weight, neonatal death, neonatal sepsis, and neonatal respiratory distress syndrome.
  
  
  RESULTS
  Of 168 women who met inclusion criteria, 75 received ampicillin and erythromycin and 93 received ampicillin and azithromycin. There was no difference in latency between groups: 9.6±13.2 days (erythromycin) compared with 9.4±10.0 (azithromycin) days (P=.40). Secondary outcomes did not differ between groups. We had 80% power to detect a difference of 5 days.
  
  
  CONCLUSIONS
  Among women with preterm premature rupture of membranes between 24 and 34 completed weeks of gestation, substitution of azithromycin for erythromycin in the recommended antibiotic regimen did not affect latency or any other measured maternal or fetal outcomes.
  
  
  METHODS
  III.
authors.affiliation: Indiana University School of Medicine and Department of Medicine, Division of Clinical Pharmacology, and Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Pierson
authors.forename: Sashana S
authors.initials: SS
authors.lastname: Gordon
authors.forename: David M
authors.initials: DM
authors.lastname: Haas
mesh_terms: D000328:Adult; D000667:Ampicillin / Q000008:administration & dosage*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D017963:Azithromycin / Q000008:administration & dosage*; D015331:Cohort Studies; D057186:Comparative Effectiveness Research; D036861:Delivery, Obstetric / Q000009:adverse effects / Q000379:methods; D016903:Drug Monitoring; D057915:Drug Substitution; D004359:Drug Therapy, Combination; D004917:Erythromycin / Q000008:administration & dosage*; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000188:drug therapy*; D006801:Humans; D007196:Indiana; D007231:Infant, Newborn; D007744:Obstetric Labor Complications / Q000517:prevention & control*; D011247:Pregnancy; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D004917:Erythromycin; D000667:Ampicillin; D017963:Azithromycin