How to Prepare for a Pelvic Ultrasound

A pelvic ultrasound scan is done or requested by your doctor to help diagnose some trouble you've been having with your uterus, ovaries and/or early pregnancy. Your urinary bladder must be full for a transabdominal pelvic ultrasound so that it will push the gas-filled intestines out of the way and make a fluid window for the ultrasound to pass through to the uterus and/or ovaries. Rumors abound about how horrible it is to have to drink all that water, hold a full bladder, or be told you're not full enough or too full so let a little bit out. Good news! There is a more comfortable way to fill your bladder and have a less worrisome examination.


  1. 1
    Check if you are having a transabdominal (full bladder) exam or an endovaginal/intravaginal (empty bladder) exam. If it's the latter, read Prepare for an Intravaginal Ultrasound. Otherwise, continue here.
  2. 2
    Realize that everyone's kidneys produce urine at a different rate, so the instructions given to you by the clinic are aimed at the patient with the slowest bladder filling time.
  3. 3
    Drink four (4) 8-ounce glasses of water one hour before the exam which is the usual requirement for the test. This means empty your bladder about 2 hrs before the exam time, then drink 32 oz of water over the next hour. Do not empty your bladder until the ultrasound technologist tells you.
  4. 4
    Start earlier if you think you will be unable to drink the full amount. If you are unable to keep the water down (vomiting), it is likely your bladder will not be full enough because you are already dehydrated. Explain this to the technologist or your doctor. They have the option of doing an endovaginal/intravaginal ultrasound instead.
  5. 5
    Drink your water a bit closer to the exam time if you drink coffee or other caffeinated products, or take a diuretic (water pill). Your bladder will fill more quickly on the day of the exam.
  6. 6
    Make sure to have breakfast on the day of the exam. Otherwise you will be dehydrated and will need more than the 4 glasses to fill your bladder. Likewise, things like partying with alcohol, a long airline flight, or too much coffee the day before the examination will also dehydrate you.
  7. 7
    Hydrate yourself well by drinking water or other clear fluids the day before the exam. On the day, you should be able to get by with only 3 glasses of water.
  8. 8
    Be aware that you may feel uncomfortable, but not painfully full when your bladder is the correct fullness. If you are painfully full, be assured that you can empty your bladder quite a bit, and you will still fill back up within 30 minutes or so if you have taken all the required fluids.
  9. 9
    Know that when the bladder is too full for the exam, it is actually in spasm so beginning to pee is difficult. Let out enough to be more comfortable (more than 2 cups), then stop the flow with the pelvic muscles, or by starting to stand up, holding toilet paper to catch any remainder. Remember, if you let out too much, you will fill back up again.


  • If you are suffering from a bladder infection on the day of the exam, try to postpone as this preparation is very uncomfortable when bladder pain is present.
  • Sometimes an endovaginal/intravaginal ultrasound will need to be done afterward to get more detailed images. You will be asked to empty your bladder completely for this part. Please read the wikiHow for Prepare for an Intravaginal Ultrasound.
  • If you are worried about losing bladder control during the examination, wear a protective pad. Be assured that this is unlikely to happen. The technologist is a professional and should be very understanding if this very unlikely event should happen.

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Categories: Pregnancy | Women’s Health