Nuchal fold thickness at 14-16 weeks' gestation as measured by transvaginal sonography

Abstract

Objective: To establish normal values of fetal nuchal fold thickness at 14-16 weeks of gestation by transvaginal sonography. Methods: Transvaginal sonography was used to measure nuchal fold thickness in 182 normal pregnancies at 14-16 weeks of gestation. Nuchal fold thickness was measured as the distance from the outer skull bone to the outer skin surface in the transverse axial image in the suboccipitalbregmatic plane of the head. Results: There was no significant association between nuchal fold thickness and gestational age (r = 0.084; P = 0.258). The mean (standard deviation) was 2.2 (0.5) mm and the 95th centile was 3.0 mm. Conclusions: The 95th centile of nuchal fold thickness measured by transvaginal sonography at 14-16 weeks is 3.0 mm.