You’ve heard the rumours but you’re still not sure – should you have a full or empty bladder before an ultrasound scan?

Before we get into that, it might be a helpful to understand the difference between the 2 main types of ultrasound you may need: trans-vaginal and trans-abdominal.

Trans-vaginal scans are an internal examination which allows a doctor to look more closely inside your body at organs such as the ovaries or womb. A small ultrasound probe with a sterile cover, not much wider than a finger, is then gently passed into the vagina and images are transmitted to a monitor. Internal examinations may cause some discomfort, but don’t usually cause any pain and shouldn’t take very long.

Trans-abdominal scans are an external ultrasound scan and most often used to examine the heart or an unborn baby in the womb. A small handheld probe is placed on your skin and moved over the part of your body being examined. A lubricating gel is put on your skin to allow the probe to move smoothly. This also ensures there’s continuous contact between the probe and the skin. You shouldn’t feel anything other than the sensor and gel on your skin (which is often cold).

So, will you need a full or empty bladder?

Generally, if you are having a trans-vaginal scan, a full bladder is not required. Trans-vaginal scans are usually booked for a gynaecological scan, or an early pregnancy scan at pre-10 weeks gestation. A full bladder could obstruct the sonographer’s view for these ultrasound scans.

If you have a scan after 10 weeks, then having water in your bladder can actually help the sonographer to see your baby more clearly! A full bladder helps by pushing the bowel out of the pelvis allowing the transmission of ultrasound to target organs more clearly.

How much should I drink?

It is advised that you should drink a litre of water about an hour before your examination. This allows time for the bladder to fill. If your bladder is not adequately full it may impact negatively on the examination. This could also be the case if it is too full and causing discomfort. Ideally, drink as much clear fluid to make your bladder comfortably full.

What should I drink to fill my bladder?

Any fluid will fill your bladder, but cold still water is ideal. Fizzy drinks should be avoided before an abdominal or pelvic scan. They can increase the amount of gas in the bowel, and this is detrimental to the scan quality.

Use the link below for more information on how to prepare for a scan with Window to the Womb:

https://windowtothewomb.co.uk/your-scan/: Do I Need To Drink Water Before My Ultrasound?