Neodymium: YAG laser hysteroscopy in large submucous fibroids. The preoperative use of a potent, subcutaneously injected gonadotropin-releasing hormone agonist (GnRH-a) was evaluated in a series of 60 women with large submucosal fibroids. Myomectomy by hysteroscopy and Nd:YAG laser was easily performed. In 12 cases, the largest portion of the myoma was not inside the uterine cavity and myomectomy was carried by a two-step hysteroscopy. In women who wished to become pregnant, a pregnancy rate of 66% was achieved. Advantages of preoperative use of a GnRH-a are (1) the significant decrease of the fibroid size, (2) a lower fluid absorption, and (3) the restoration of a normal hemoglobin concentration. 