Carol, mom to 7
I agree with the other readers...your odds are still fantastic even if you are no longer in the 1500 range.
Look at it this way...if you divide 1 into 873, you only have a 1000th percent chance of having a baby with DS.
I read a great article about this and it said to think of the odds this way...
If a 45+ year old woman has a 1 in 8 chance of having a baby with any type of chromosomal defect, that's still only a 12% chance. She has an 88% chance of having a normal chromosomal baby.
Also, I recently visited the National Down's Syndrome website to learn more about odds, birth defects, heart defects, etc. and learned that 80% of DS babies are born to women age 35 and YOUNGER. Why? B/c statistically, the have more babies than women in our age group.
I agree with one of the other readers, if you really need certainty or if the answer will change the outcome of your pregnancy (whether or not you'd carry to term) than by all means have the amnio or CVS done. It is a very personal decision.
I'm 40 1/2, pregnant with our 3rd baby and if my NT results come back normal, but my triple or quad screen markers come back elevated, I'm just leaving it alone.
Best of luck!