I had an amnio. The reason I had this was that I had a 1/37 chance of having a DS baby. This was mainly due to age (will be 42 when bubs is born) but also had a 4.2 NT measurement at the 12 week scan. At that time I was waiting to see my current OB for the first time (a different OB who I decided not to continue with had given me the referral for the scan) and got phone calls from both OB's and both recommended an amnio not a CVS. CVS has double the m/c risk and is not as accurate as an amnio (pretty close though). Regardless of what test you have you can still have a good result (no abnormalities detected) and still go on to have a baby with a chromosonal problem as neither test is 100% (this is extremely rare, but does happen).

If I were you I'd only have such a test if you considered a high risk and would abort if certain trisomies were detected. I say this because of the worry you get with the two week wait you get with such tests (FISH results come back in 24 hours, but you still have to wait for the final results to be given the all clear), during which period you are also at a higher risk of miscarriage. It's a really difficult time, and if it's not necessary, best avoided.

If you would keep the baby anyway, then the best thing to do is avoid such invasive testing as most babies with chromosonal problems do show other signs on ultrasounds later on, so you'd most likely know before the birth so you could prepare, although some show no signs at all and are only detected at birth.

The actual experience of the amnio was quite an easy one for me. No pain, no discomfort, nothing. It was the wait for the results that was the killer.