Depending on which stage of pregnancy they are done at, scans can: It can do, but not usually until you have an anomaly scan at around 20 weeks of pregnancy.

The combined results of this test combined with a nuchal translucency scan will be used to calculate the chance of your baby developing Down’s Syndrome.

If you haven’t had the combined nuchal scan and blood testing for screening for chromosome abnormalities, you’ll be offered a screening blood test between 14 and 20 weeks.

An ultrasound scan sends high-frequency soundwaves through your uterus (womb).

These bounce off your baby and the echoes are turned into an image on a screen that shows your baby's position and movements.

Your sonographer (the person performing the scan) will look at these shades to interpret the images.

Most parents look forward to their scan because it gives them a first glimpse of their baby.

The diagnostic tests that five a definitive yes or no can carry a small risk of miscarriage because it involves removing a tissue or fluid from inside the womb for testing.

If screening tests show a lower risk, most parents choose not to put themselves, or their unborn baby through further, more invasive tests.

It is to check that your baby is developing normally.