(1) Congenital heart disease: The NT value is high, and whether the fetus has congenital heart disease should be considered first. 13 congenital heart disease will be accompanied by chromosomal abnormalities, and13 chromosomal abnormalities will be accompanied by congenital diseases. Therefore, NT value is highly correlated with congenital heart disease.
(2) Chromosome abnormality: Chromosome abnormality is the main cause of perinatal death and birth defects, often accompanied by heart and other organ abnormalities. Recent studies have shown that nt is related to a variety of fetal abnormalities, and the incidence of cardiovascular system abnormalities in children with NT thickening has increased significantly.
(3) Abnormal development of thoracic cavity or lymphatic vessels: The pressure in the thoracic cavity increases due to various reasons, which can hinder venous return and venous congestion. When venous blood returns to the head of the neck, the transparent layer of the neck thickens; Delayed and blocked development of the lymphatic system caused by various reasons will lead to the lymphatic system not flowing back smoothly and accumulating in the fetal neck.
In addition, congenital infection, anemia, hypoproteinemia, maternal malnutrition and so on. , it will also lead to NT thickening.