In addition to structural screening, the present
study found 16 cases (2.7%) to have NT thickness of
more than 95 percentile for each gestational age, but
half of them (50%) had normal karyotype and had no
gross anomaly at birth. However, NT measurement has
been proven to be effective in screening for aneuploidy
and subsequently obvious structural anomalies,
especially congenital heart defects. Although, the
efficacy of NT measurement can not be well analyzed
in the present study due to a relatively small sample
size, the present result suggests that the first trimester
scan may not only be beneficial in diagnosis of anomaly
at the time of scanning, it can also identify the higher
risk group based on NT and warrant obstetricians to
follow-up and make diagnosis of anomaly later. Even
in the absence of aneuploidy, nuchal thickening is
clinically relevant because it is associated with an
increase in adverse perinatal outcome caused by a
variety of fetal malformations, especially congenital
cardiac defects(5,14,17)