Background: Fetal membrane rupture prior to the 37th week of gestation is a condition termed preterm premature rupture of membranes (PPROM). Many institutions now recommend azithromycin over erythromycin in management of PPROM Due to national erythromycin shortages, azithromycin's better side effect profile, and ease of administration.  
Aim of work: Assess effectiveness, side effects, and cost of azithromycin versus erythromycin in management of PPROM. 
Patients and methods: this research involved women with PPROM who were distributed into two groups; group A (Azithromycin treated group) and group B (Erythromycin treated group). All cases underwent full history taking, clinical examination, laboratory analysis and obstetric ultrasound (including AFI and FHR). Different outcomes were determined including the duration of latency, chorioamnionitis, neonatal death, neonatal respiratory distress, drug prices and effects.
Results: Differences between groups have been shown to be statistically significant as regard incidence of nausea, vomiting and diarrhea. Higher incidence of side effects was detected among erythromycin than Azithromycin group. The cost of azithromycin was higher compared to the erythromycin regimen.
Conclusion: Azithromycin can be used in place of erythromycin for the expectant management of PPROM. Azithromycin only benefits from its availability and reduced gastrointestinal side effects..