i was due for mine in the middle of my pregnancy so they did it at the start and it came back "abnormal" which he said is very common for ones done during pregnancy so we'd have to redo after bubs was born - at which it came back fine. if it was so common for them to come back with abnormal when you are pregnant I dont understand why they push to get them done during pregnancy just so they can freak you out with the result for the next 8 months. again though they only do them early on from my experience so yes it depends on where you are in your pregnancy. also if it does come back truly abnormal I don't know that there is much they can do while you are pregnant anyway - might be wrong here.