Medical EV problem

[malorum]

In the UK a blood test is taken from pregnant women to determine their risk of having a downs syndrome child.

the test can identify the "high risk" of 1 in 300.

If the risk is in this region an amniocentesis is normally performed which will give a near certain diagnosis but carries with it a 1 in 50 chance of causing an abortion.

So the diagnositc proceedure has a higher risk of fetal death, than the risk of disability used to justify the test.

I am guessing the assumption is that the negative utility of having a disabled child is much higher than the negative utility of accidentally killing the unborn feotus.
An example of how "pure EV" is not applied in the scientific field.

thoughts plz