Objective To evaluate the effect of transabdominal amnioinfusion on prolongation of pregnancy, and maternal and neonatal outcomes in preterm premature rupture of membranes (pPROM). Methods We conducted a prospective randomized controlled study of women with pPROM during singleton live pregnancy—between 26 and 33 + 6 weeks—whose amniotic fluid index (AFI) was less than the 5th percentile. The study group underwent transabdominal amnioinfusion at admission and then weekly if their AFI fell below the 5th percentile again. The control group received expectant management. Results The difference in the mean interval from pPROM to delivery between the groups was not statistically significant. Neonatal and maternal outcomes were significantly improved in the study group compared with the control group (fetal distress [10% vs 37%]; early neonatal sepsis [17% vs 63%]; neonatal mortality [17% vs 63%]; spontaneous delivery [83% vs 53%]; and postpartum sepsis [7% vs 33%]). Conclusion Transabdominal amnioinfusion reduced fetal distress, early neonatal sepsis, and neonatal mortality. In the study group, more participants delivered spontaneously and there were fewer cases of postpartum sepsis, although the pPROM–delivery interval was not increased.