The use of advanced composites in primary structures has intensified the need to develop experimental procedures and techniques that allow characterization of mechanical properties of composites at high levels of robustness, accuracy and reliability. Among various failure modes, delamination is one of the most common damage types in structural composites. Most of the works available in the open literature are focused on unidirectional laminates, where there is a clear a lack of knowledge regarding the behaviour of composite fabrics under cyclic loading. The characterization of fatigue related mechanical properties and better understanding on the material behaviour under cyclic loading are key points to develop criteria and design procedures for damage tolerant composite aerostructures. The main objective of this work is to evaluate the effect of mean stress and changes on initial compliance for mode I fatigue interlaminar fracture process, focusing on methods to reduce efforts in experimental procedures and improve structural efficiency in the design of composite aeronautical structures. Fatigue tests were conducted on the Double Cantilever Beam (DCB) specimen made by Hexcel® AS4 8552 Plain Weave Fabric. The delamination growth rate, da/dN, was determined as a function of the maximum Mode I strain energy, GImax, considering a exponential fitting function according to the Compliance Based Beam Method (CBBM) in agreement with the ASTM D5528-13 (2013) and ASTM E647-15 (2015). Simplifications include the definition of the crack length (a) as a function of compliance (C) and number of cycles (N), respectively, Simple Moving Average (SMA) procedure and polynomial adjustments, which yields to less scatter in results compared to classical data reductions techniques and satisfy basic assumptions for fatigue crack propagation. The delamination growth rate curve proved to be strongly affected by the applied mean load and also by the initial compliance. Considering the stable propagation region on the fatigue crack propagation curve, steeper curves were reported for higher load levels and higher initial compliance values, which implies in a higher delamination growth rate as a consequence of an increase in applied mean stress and initial crack length. Finally, fractographic analysis were conducted to investigate the effects of cyclic loading and the main load levels on fracture surfaces. It is observed that roughness and morphology of fracture features were modified by different load levels.