Aim: Aim of this study is investigate the collagen amounts that have been deposited within the chorioamnionic membranes of term pregnancies by means of electron microscopy. Material and Methods: The study group was made up by 20 women with term pregnancies who were diagnosed with premature rupture of membranes (PROM). Control group consisted of 20 women with term pregnancies who had no leakage of amniotic fluid. Electron microscopy was utilized to assess the collagen amount within the tissue samples which were acquired from the chorioamnionic membranes of the patients. Results: When the control group was compared with the study group, term pregnancies with PROM were found to have statistically lower quantity of collagen within unit area of chorioamnionic membranes(Mean values are respectively 69.5% ± 26.3% vs 49.60% ± 23.44%; p=0.017; 95% confidence interval: 0.14-0.19) Conclusion: Many factors have been implicated in the etiology of PROM. The present study concludes that the decrease in collagen quantity is statistically significant in chorioamnionic membranes of term pregnant women with PROM.