First-trimester aneuploidy screening: is there a maternal age at which it loses effectiveness?

Objective: To determine the maternal age at which the likelihood of a "screen-positive" result justifies diagnostic testing.

Study Design: A retrospective review of women who presented for first-trimester screening using nuchal translucency (NT) measurements with or without serum biochemistry between January 2000-December 2011. Using cutoffs of 1:300, 1:270, and 1:200, the Trisomy 21 (T21) screen-positive rates were stratified by maternal age.