Normally, your healthcare provider will provide you with recommendations on how to prepare for an ultrasound procedure. Generally, it is advised to drink a minimum of 24 ounces of clear fluid at least one hour before the appointment. In the vast majority of cases, no sedation or fasting is required unless the vaginal ultrasound is part of another procedure that requires anesthesia. Keep in mind that based on your medical condition, your doctor might request specific preparation.