Patients were prepared for ET with oral E2 to attain endometrial thickness ≥ 8 mm and triple line pattern on ultrasound scans. At that time, patients were given 100 mg of IM progesterone in oil daily and ET was preformed three days later under abdominal ultrasound guidance as described earlier. Oral E2 and progesterone were continued until documentation of fetal heart activity by ultrasonography.