Ovarian stimulation
CAVITY
All patients were randomly allocated into four groups: minimal-OS with r-FSH (Minimal-FSH), minimal-OS with HP-HMG (Minimal-HMG), mild-OS with r-FSH (Mild-FSH) and mild-OS with HP-HMG (Mild-HMG). Patients in group of the Minimal-FSH received 100 mg/day CC during the menstrual cycle days, 3rd -7th, and 150 IU/day Gonal-F (Follitropin alfa, Merck Serono, Germany) from the day 7 of the menstrual cycle. Patients in group of Minimal-HMG received 100 mg/day CC during the menstrual cycle days, 3rd -7th and 150 IU/day Merional (Highly Purified Menotropin, IBSA, Switzerland) from the day 7 of the menstrual cycle. Patients in group of Mild-FSH received 150 IU/day Gonal-F from day 3 of the menstrual cycle. Patients in group of Mild-HMG received 150 IU/day Merional from day 3 of the menstrual cycle.All participants received 0.25 mg Cetrotide (Cetrorelix acetate, Merck Serono, Switzerland) daily since at least one dominant follicle reached a maximum size of 12 mm. Next, 500 µg Ovitrelle (Choriogonadotropin alfa, Merck Serono, Switzerland) was prescribed when at least three follicles reached a size of 17–18 mm. 34–36 h after triggering, ovum pick up was performed. Two to three days after oocyte retrieval, 1–2 fresh embryos at the cleavage stage were transferred into the uterine cavity using the embryo transfer (ET) catheter (Labotect Gmbh, Labor-Technik-Gottingen Kampweg 12, 37,124 Rosdorf, Germany). In all patients, fresh ET was achieved without anesthesia and any difficulty in transfer. Luteal phase was supported by 400 mg twice a day for 14 days of vaginal progesterone (Cyclogest progesterone, Actavis, Barnstaple, EX32 8NS, UK). Progesterone therapy was continued until pregnancy test was performed and in case of positive pregnancy, administration of progesterone suppository continued until 12 weeks of gestation.Based on the guidelines 2016 from the Royal College of Obstetricians & Gynaecologists (RCOG) [