Has anyone had this done in their pre-natal testing??

Basically, I had a CVS testing done because of an increased thickness of the neck noted during my NT scan. Thankfully, the CVS testing come back all normal. I thought for sure we were in the clear, but now my perinatal OB wants to further test the sample from the CVS testing to look for other syndromes that aren't looked for during a CVS or amnio testing.

Just wondering if anyone had this done. My insurance won't cover it since it is a relatively new testing procedure, and it's an expensive cost we are not sure we want to take. But finding out the results could be priceless, KWIM?

TIA!