The effect of nuchal cord on nuchal fold thickness measured in the second trimester

To find out whether nuchal cord causes an effect on the nuchal skin fold thickness (NFT) measurements, or not.

A total of 242 fetuses with normal outcomes that had undergone detailed second trimester US scan between 18 and 24 weeks of gestation were included in the study. NFT measurements were made on axial cranial US images passing through the cerebellum and cavum septi pellucidum. To detect nuchal cord, color Doppler imaging was performed on the axial views of the fetal neck. To investigate the differences in NFT measurements of the fetuses with or without nuchal cord, statistical analysis was performed using Mann-Whitney test. P < 0.05 was considered statistically significant.

The study group was divided into two groups: nuchal cord (+) (n: 26) and nuchal cord (-) (n: 216) fetuses. Mean NFT measurements were 4.66 ± 0.64 mm and 4.36 ± 0.79 mm for nuchal cord (+) and nuchal cord (-) fetuses, respectively. Median NFT measurement for nuchal cord (+) fetuses was 4.6mm, whereas it was 4.4mm for nuchal cord (-) fetuses. Statistically significant difference was denoted between two groups, in terms of NFT measurements (P = 0.049).

NFT measurements of fetuses with nuchal cord are higher than the NFT measurements of fetuses without nuchal cord. One can conclude that the nuchal cord (+) fetuses with no other anomalies but increased NFT should be re-scanned to see if the increased NFT resolves in the absence of nuchal cord.