Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Number of Invasive Procedures Before and After First Trimester and Stepwise Sequential Screening Availability
| Procedure | Pre-FTS | FTSa only | SSb Avail | p, pre-FTS vs FTS only | p, FTS only vs. SS avail |
|---|---|---|---|---|---|
| Amniocentesis | 1,632 | 793 | 655 | p < 0.0001 | p < 0.0001 |
| CVS | 494 | 399 | 371 | P < 0.001 | P = 0.31 |
aFirst trimester screening
bSequential screening
