According to Web MD, the risk that amniocentesis could cause a miscarriage is approximately 1 in 200 to 1 in 400. Even if your false number were correct, no sane person would consider that an acceptable risk to the child just to satisfy the parent’s curiosity over something that would be revealed at birth with no risk to anyone.
http://www.webmd.com/baby/guide/amniocentesis?page=3
1/200 is a dinosaur number from the 1980’s. WebMD should be updated.
The accepted number is 1/1600:
“The amniocentesis-related potential fetal loss was calculated based on the traditional fetal loss rate of 1/200 as well as the recently published loss rate of 1/1600 ...
CONCLUSIONS:
Our analysis suggests that the benefit of genetic amniocentesis for the sole indication of AMA far outweighs the potential amniocentesis-related fetal loss rate...
http://www.ncbi.nlm.nih.gov/pubmed/18999912
“Eddleman et al compared pregnancy losses between 31,907 women in the FASTER trial who did not undergo amniocentesis with 3096 who did, and found that the difference between the 2 groups was 0.06% or 1/1600. 21
Odibo et al compared outcomes in 11,746 women undergoing amniocentesis with 39,811 controls not having amniocentesis.23 The fetal loss rate prior to 24 weeks was not significantly different between the 2 groups
...Compared to amniocentesis, CVS may be associated with a higher pregnancy loss rate (defined either as total losses or losses up to 28 weeks) of 0.9% (Table 1).
Several cell-free fetal DNA and RNA technologies are under development to test a pregnancy for aneuploidy, mostly focusing on Down syndrome testing. Sampling of cffDNA from maternal blood for analysis by massively parallel sequencing (MPSS) is estimated to have a sensitivity of between 96 and 100%, and a specificity between 94 and 100% for detecting Down syndrome. It can be performed at 10 weeks of gestational age. (Wikipedia)
That, of course, still leaves the moral issue that 92% of diagnosed Down's children are aborted. With no risk and very high selectivity and specificity, however, it will not be possible to argue against testing. MPSS sequencing of cffDNA also tests for other conditions. It will become standard for all pregnancies.
Abortion in the case of a positive DS diagnosis will remain both a public policy and personal morality issue, but many of the concerns discussed above will become mute.