Ultrasonographic measurement of fetal nasal bone length in the second trimester in Korean population

Abstract

We present the normal range of NBL in the second trimester in the Korean population and also their linear relationship with gestational age (GA). The NBL appears to be shorter in Korean fetuses than Caucasian and Chinese fetuses. This indicates that the normal range would vary between races and that a relative percentile is a more reliable screening criterion than an absolute value.