The strategy of in vitro fertilization (IVF) procedures relies on the increasing pregnancy rate and decreasing the risk of premature ovulation and ovarian hyperstimulation syndrome. They are also designed to avoid weekend oocyte retrievals. Combined oral contraceptive (OC) pills are among the medicines used to accomplish these objectives. Alternatively, estradiol can be used instead of OC to obtain similar results. The aim of our study was to compare the differences in pregnancy rates (PRs), implantation rates, and miscarriage rates between a short agonist protocol with estradiol priming and a long protocol with combined OC. Of the 298 women who participated in this study, 134 achieved clinical pregnancies (45.0%). A higher PR (58.4%, n = 80, compared to 40.3%, n = 54) was achieved in the long protocol after OC pretreatment group. The implantation rate was also higher for this group (37.8% versus 28.0%; P = 0.03). The miscarriage rate was 15.0% (n = 12) for the long protocol after OC pretreatment group and 20.4% (n = 11) for the short agonist group (P = 0.81). The short agonist protocol required a 5.7% lower human menopausal gonadotropin (hMG) dosage than the long protocol but surprisingly the number of oocytes retrieved was also smaller.