Objective: To evaluate the impact of myomectomy on in vitro fertilization-emb ryo transfer (IVF-ET) and oocyte donation cycle outcome. Design: Retrospective case-controlled study of consecutive fresh IVF-ET and oocyte donation patients during a 2-year interval. Setting: Private assisted reproductive technology (A RT) center. Patient(s): Patients with submucosal leiomyomata resected hysterosco pically (group A: 15 oocyte donor recipients; group 1 = 31 IVF-ET patients) and those with intramural components or strictly intramural leiomyomata that distor ted or impinged upon the endometrial cavity resected at laparotomy (group B = 26 oocyte donor recipients; group 2 = 29 IVF-ET patients). Intervention(s): Precy cle hysteroscopic or abdominal myomectomy and subsequent fresh IVF-ET or oocyte donation. Main Outcome Measure(s): Results of controlled ovarian hyperstimulati on as well as ongoing pregnancy and implantation rates were evaluated in compari son with contemporaneous patient groups without such lesions (group C = 552 oocy te donor recipients; group 3: 896 IVF-ET patients). Result(s): As would be expe cted, the mean number and size of leiomyomata were significantly larger in patie nts who underwent abdominal myomectomy. However, neither ongoing pregnancy nor i mplantation rates were significantly different in comparison with controls among either oocyte donor recipients (group A: 86.7%, 57.8%; group B: 84.6%, 55.2 %; group C 77%, 49.1%). The findings were similar for those undergoing IVF-E T in comparison with controls (group 1: 61%, 24%; group 2: 52%, 26%; group 3 : 53%, 23%). Conclusion(s): Precycle resection of appropriately selected clini cally significant leiomyomata results in IVF-ET or oocyte donation cycle outcom es that are similar to controls. Objective: To evaluate the impact of myomectomy on in vitro fertilization-emb ryo transfer (IVF-ET) and oocyte donation cycle outcome. Design: Retrospective case-controlled study of consecutive fresh IVF-ET and oocyte donation patients during a 2-year interval Patient (s): Patients with submucosal leiomyomata resected hysterosco pically (group A: 15 oocyte donor recipients; group 1 = 31 IVF-ET patients) and those with intramural components or strictly intramural leiomyomata that distor ted or impinged upon the endometrial cavity resected at laparotomy (group B = 26 oocyte donor recipients; group 2 = 29 IVF-ET patients). Intervention (s): Precy cle hysteroscopic or abdominal myomectomy and subsequent fresh IVF-ET or oocyte donation. Main Outcome Measure (s): Results of controlled ovarian hyperstimulati on as well as ongoing pregnancy and implantation rates were as in compari son with contemporaneous patient groups wit hout such lesions (group C = 552 oocy te donor recipients; group 3: 896 IVF-ET patients). Result (s): As would be expe cted, the mean number and size of leiomyomata were significantly larger in patients who underwent abdominal However, neither ongoing nor norplantation rates were significantly different in comparison with controls among either oocyte donor recipients (group A: 86.7%, 57.8%; group B: 84.6%, 55.2%; group C 77%, 49.1%) . The findings were similar for those undergoing IVF-E T in comparison with controls (group 1: 61%, 24%; group 2: 52%, 26%; group 3: 53%, 23% Precycle resection of suitably selected clini cally significant leiomyomata results in IVF-ET or oocyte donation cycle outcom es that are similar to controls.