Prenasal thickness in trisomy‐21 fetuses at 16–24 weeks of gestation

Abstract

The fetal profile is routinely examined during the second-trimester scan and therefore the skill needed to obtain the view necessary for the measurement of prenasal thickness is widely available. If the finding of our study--that in more than 70% of fetuses with trisomy 21 prenasal thickness is above the 95(th) centile--is confirmed in prospective screening studies this measurement alone could prove a highly sensitive method of second-trimester screening for trisomy 21.