 Gonadotropin-releasing hormone analogue GnRH-a is a synthetic decapeptide compound which can down-regulate pituitary function causing a temporary low estrogen state. Since endometriosis is an estrogen-dependent disease, the use of long-acting GnRH-a can control the growth of endometriosis by inhibiting ovary function.Some scholars have found that, for adenomyosis patients who received a super long protocol pretreatment of long-acting GnRH-a for 1-2 months in IVF treatment, the pregnancy outcome is comparable to that of the controls with normal uterus. Thus, the aim of this study is to compare the clinical pregnancy rate in patients treated with GnRH-a for 1, or 2 months. 