A total of 143 women were recruited. In 119 fetuses, facial profiles were successfully obtained and the presence or absence of nasal bones was assessed. One hundred and fourteen fetuses had normal karyotypes. The rate of absence nasal bone when assessed between 11-14 weeks was 0.88% in the fetuses with a normal karyotype. During the same period, 2 out of 3 fetuses with Down syndrome had absence of nasal bones