“…Characteristics of the included studies are given ( Table 1 ). In our systematic review the classification systems used included ( Table 2 ) those from the American Fertility Society [ 9 , 16 , 27 , 28 , 34 – 36 , 41 , 44 , 45 ], European Society of Gynaecological Endoscopy [ 7 , 29 , 39 ], American Society for Reproductive Medicine [ 11 ], European Society of Hysteroscopy [ 29 , 38 ], European Society of Human Reproduction and Embryology [ 45 ], modified Sugimoto criteria [ 13 ], and the March classification system [ 18 ]. Three studies [ 7 , 29 , 45 ] reported the stages of adhesion using 2 classification systems; however, several studies [ 8 , 12 , 19 , 30 – 33 , 37 , 42 , 43 ] did not provide any information of the classification system used.…”