Results of routine fetal nuchal translucency measurement at weeks 10-13 in 4233 unselected pregnant women.

The aim of this study was to determine the value of nuchal translucency (NT) measurement for the detection of aneuploidies and other malformations in a low-risk population. In total, 4233 women who booked in our hospital for delivery were examined between the tenth and 13th week of gestation. Of the 17 chromosomal abnormalities that occurred, 11 were detected using the measurement of NT (65 per cent). Only three of the seven Down syndrome pregnancies were detected using this technique (43 per cent). The remaining four Down syndrome babies were diagnosed either because of positive biochemical testing or by amniocentesis because of maternal age. A total of 69 serious malformations including chromosomal defects were detected during the study period. In 18 of these cases, the NT measurement was > or = 2.5 mm (26 per cent). Most of the malformations without aneuploidies were of cardiac origin. The data show that the NT measurement is a valuable marker for aneuploidy even in a low risk-population. It is also of value in the diagnosis of other serious malformations, particularly cardiac defects.