Nasal bone hypoplasia: is it a common finding amongst chromosomally normal fetuses of southern Chinese women?

Abstract

Objective: To assess the incidence of nasal hypoplasia among fetuses of southern Chinese women.

Methods: This prospective observational study was conducted at Princess Margaret Hospital, Hong Kong. All pregnant women referred for chromosomal studies before 14 weeks were assessed. The crown-rump length, nuchal translucency thickness, and nasal bone were assessed between 11 and 14 weeks.

Results: 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. A nasal bone was visualized in one fetus with Edward syndrome and the other with Turner syndrome (45 X).

Conclusion: The incidence of nasal hypoplasia is not increased among fetuses of southern Chinese women. Assessment of ossification of the nasal bone can be used to supplement first-trimester screening in Chinese women.