**3.2. Mild endometriosis Vs severe endometriosis prior to IVF/ICSI**

The same study (15) reported that the probability of pregnancy was reduced in women with severe endometriosis as compared to those with mild disease.

Contrarily, a recent retrospective poorly designed study (16) demonstrated that ovarian endometriosis does not reduce IVF outcome compared with tubal factor. Furthermore, laparoscopic removal of endometriomas does not improve IVF results, but may cause a decrease of ovarian responsiveness to gonadotropins. Nevertheless, they included a bizarre group of patients with one or more endometrioma, unilateral or bilateral with a size of6 cm and more importantly symptomatic as well as asymptomatic cases. In addition to being a retrospective analysis, these heterogenous criteria would weaken this study. We believe that stripping off cyst wall of a unilateral endometrioma wouldn't be expected to affect ovarian reserve or ovarian response to gonadotropins.
