The fetal heart or the lymphatic system or …? The quest for the etiology of increased nuchal translucency

Increased nuchal translucency thickness and normal karyotype: time for parental reassurance

“…Syndromes manifesting themselves as skeletal or neuromuscular disorders were the most common and these were all detected prenatally. The nuchal fluid accumulation in these cases may be caused by impaired venous return to the heart due to the small thorax, altered composition of the extracellular matrix or impaired lymphatic fluid drainage9, 11.…”

“…The number of known syndromal developmental disorders signalled by association with an increased NT at 11–14 gestational weeks is constantly growing8. Different pathophysiological explanations have been proposed for excessive nuchal fluid accumulation in early pregnancy9–11; it is likely that it is a common symptom of various different developmental disorders.…”

Persistence of Nuchal Edema and Distended Jugular Lymphatic Sacs in Noonan Syndrome

“…A delayed or disturbed jugular lymphatic development leads to distension and subsequently the ultrasonographic appearance of the jugular sacs. The disrupted jugular lymphangiogenesis causes nuchal edema and was recently described as a common denominator in the pathophysiology of the increased NT [8][9][10] . After reorganization of the JLS into lymphatic nodes and connection to the venous system, the fluid accumulation can drain away and the NT resolves [7] .…”

A newly described thoracic vascular malformation in fetuses with Down syndrome

“…The likely explanation for our novel finding is that either this tumor regresses with advancing gestation or it remains undiscovered after delivery. Although it is possible to postulate that a fetal hyperdynamic circulation as a consequence of blood shunting within the vascular tumor may contribute to the development of cardiac strain and increased NT3, 4, it should be noted that the majority of fetuses with increased NT do not have vascular tumors. As Doppler artifacts can easily be obtained in the proximity of skeletal structures, the presence of the mass had to be confirmed at different angles of insonation to exclude false positive findings.…”