Preterm Premature Rupture Of Membranes (PPROM) is directly linked to prematurity associated with severe neonatal morbidity and mortality. Randomized clinical trials have shown that weekly injections of 17-alpha-hydroxyprogesterone (17P) or daily vaginal progesterone application decreases the number of preterm deliveries, particularly for women with a history of preterm delivery or those with a shortened cervix. However, no studies have yet been conducted to prove or disprove the effect of rectal progesterone on latency period. To address this issue,<strong> </strong>we will conduct a multicenter randomized triple-blind controlled trial of 216 participants (108 in each group) from January 1, 2016 to August 31, 2016. Inclusion criteria, exclusion criteria, data collection procedure, data analysis, and assessment of safety procedures are explained in the study protocol.<strong> </strong>The primary objective will be to determine the effect of rectal progesterone on the latency period in PPROM. The secondary objective will be to study the effect of rectal progesterone on maternal outcomes of hospitalization, intensive care unit admission, chorioamnionitis, post-partum hemorrhage, post-partum pyrexia, endometritis, and maternal death. In addition, we will evaluate prenatal birth weight, Apgar score, neonatal morbidity, duration of neonatal intensive care unit stay, intrauterine fetal death, and neonatal death associated with PPROM.