“…To the best of our knowledge, nine original studies have been published using this study design, most of them during the past 3 years (Ballester et al, 2012;Chiang et al, 1999;Costello et al, 2011;Martínez-Conejero et al, 2011;Maubon et al, 2010;Mijatovic et al, 2010;Salim et al, 2012;Thalluri and Tremellen, 2012;Youm et al, 2011). Results from these contributions, however, are conflicting, with four of them suggesting an association (Ballester et al, 2012;Maubon et al, 2010;Thalluri and Tremellen, 2012;Youm et al, 2011) and five failing to document any statistically significant effect (Chiang et al, 1999;Costello et al, 2011;Martínez-Conejero et al, 2011;Mijatovic et al, 2010;Salim et al, 2012). Differences in study design, study power, criteria and instrument used to diagnose adenomyosis and choice of controls may explain these discrepancies (Vercellini et al, 2014).…”