RESUMO
OBJECTIVE: To compare the new delayed start protocol against the conventional gonadotropin (Gn)-releasing hormone antagonist protocol in poor responders (PORs). STUDY DESIGN: A total of 160 women with poor response to previous in vitro fertilization (IVF) cycle were randomized either to start Gn then Cetrotide 0.25 subcutaneously (sc) added when leading follicle (DF) reach >12 mm or Cetrotide 0.25 mg sc started first from day 2 to day 8 then Gn therapy was added and Cetrotide restarted when DF reach >12 mm. RESULTS: There was a statistically significant difference between conventional and delayed start protocols regarding the needed dose of Gn for stimulation (4368 ± 643 and 3798 ± 515), level of estradiol (E2; 778 ± 371 and 1076 ± 453), and endometrial thickness at human chorionic gonadotropin triggering (8.6 ± 1.8 and 9.8 ± 1.9), the number of DF (3.4 ± 1.5 and 4.9 ± 2.1), the number of retrieved follicles (2.4 ± 2.1 and 4.3 ± 2.5), and successful embryo transfer (13 vs 16), respectively (P < .05). There was a highly statistically significant difference between the 2 study groups regarding the number of oocytes fertilized (1.2 ± 2.0 vs 3.3 ± 1.4), metaphase II oocytes (0.9 ± 1.0 vs 2.7 + 1.6), and grade I embryos (0.7 ± 0.9 vs 2.1 + 1.1; P < .001). The chemical pregnancy, clinical pregnancy, and abortion rate showed a statistically significant difference between the 2 study groups (P value .003 and .006, respectively). CONCLUSION: Delayed start protocol significantly improved clinical pregnancy rate and IVF cycle parameters in PORs.