This is a pilot randomized controlled trial to assess the pharmacokinetics and pharmacodynamics of azithromycin in pregnant singletons admitted with preterm premature rupture of membranes (PPROM) at 24 0/7- 33 0/7. Participants will be randomized 1:1 to either 1000mg azithromycin orally once or 500mg azithromycin orally daily for seven days in addition to standard care. During the course of eight days participants will have serial collection of amniotic fluid, maternal serum; and at delivery, of placenta, membrane, and cord blood. After delivery, neonatal respiratory samples will be collected as well.
