Ideally, there are many times ultrasound examination during ovulation induction. These examination are time and money consuming. Planning a single ultrasound examination at 12th days is necessary from the point view of developing country to reduce a cost. Mature follicle has signifi cant correlation with progesterone level during single ultrasound evaluation at 12th days. But none of these parameters ultrasound (mature follicle, endometrial thickness and triple line pattern) could predict ovulation
