downs screening nuchal translucency

I'm a little confused on screening methods offered.
Am I right in thinking that all women are offered 'Triple Test',
but then who is screened with nuchal translucency combined test?

thanks for help!!

There are many different combinations for screening for Downs syndrom;
main ones are as in the table in this hyperlink:
http://www.ncchta.org/pdfexecs/summ711.pdf

At wk. 10 Combined test (NT+ BLOOD TEST )(S-Bhcg+PAPP-A)
At 14-20 weeks Quadruple test: (AFP+BHCG+PAPP-A+INhibin A)

At 14-20 weeks Triple test: (AFP+BHCG+uE2)

Usual Policy is:
All patients should be offerred Combined test provided they attend ANC between 11-13+6 days.
If they miss this timing or the CRL (crown rump length at scan maeasure >78mm --> they are offerred Triple test.
as a screening test.