Pregnancy rate in women with adenomyosis undergoing fresh or frozen embryo transfer cycles following gonadotropin-releasing hormone agonist treatment

Objective: To determine the preferred regimen for women with adenomyosis undergoing in vitro fertilization (IVF), we compared the IVF outcomes of fresh embryo transfer (ET) cycles with or without gonadotropin-releasing hormone (GnRH) agonist pretreatment and of frozenthawed embryo transfer (FET) cycles following GnRH agonist treatment. Methods: This retrospective study included 241 IVF cycles of women with adenomyosis from January 2006 to January 2012. Fresh ET cycles without (147 cycles, group A) or with (105 cycles, group B) GnRH agonist pretreatment, and FET cycles following GnRH agonist treatment (43 cycles, group C) were compared. Adenomyosis was identified by using transvaginal ultrasound at the initial workup and classified into focal and diffuse types. The IVF outcomes were also subanalyzed according to the adenomyotic region. Results: GnRH agonist pretreatment increased the stimulation duration ($11.5{\pm}2.1days$ vs. $9.9{\pm}2.0days$) and total dose of gonadotropin ($3,421{\pm}1,141IU$ vs. $2,588{\pm}1,192IU$), which resulted in a significantly higher number of retrieved oocytes ($10.0{\pm}8.2$ vs. $7.9{\pm}6.8$, p=0.013) in group B than in group A. Controlled ovarian stimulation for freezing resulted in a significantly higher number of retrieved oocytes ($14.3{\pm}9.2$ vs. $10.0{\pm}8.2$, p=0.022) with a lower dose of gonadotropin ($2,974{\pm}1,112IU$ vs. $3,421{\pm}1,141IU$, p=0.037) in group C than in group B. The clinical pregnancy rate in group C (39.5%) tended to be higher than those in groups B (30.5%) and A (25.2%) but without a significant difference. Conclusion: FET following GnRH agonist pretreatment tended to increase the pregnancy rate in patients with adenomyosis. Further largescale prospective studies are required to confirm this result.