article 2018 [Effect of gonadotropin-releasing hormone agonist used before surgery on natural pregnancy rates in patients with ovarian endometriomas]. Zhonghua fu chan ke za zhi ·doi:10.3760/cma.j.issn.0529-567x.2018.10.006 The use of GnRH-a preoperatively may have a negative effect on natural pregnancy rates of patients after surgery with ovarian endometriomas.