Premature rupture of membranes (PROM) is a major cause of perinatal mortality and morbidity associated with preterm delivery in a third of cases. Fetal survival is even more compromised when the membranes rupture early in the second trimester (very early PROM). Survival is associated with problems of delivery of the very preterm fetus as well as associated risks of feto-maternal infection. In the context of studies of amnioinfusion, very early rupture of membranes is defined as rupture between 16 and 26 weeks of pregnancy.