The NT test is done by ultrasound and is an important indicator of fetal anomalies by measuring the thickness of the posterior nuchal translucency by ultrasound, which is performed between (11-13) weeks + 6 days of gestation and requires the fetus to be positioned in a natural position with the neck in the front and side. If the NT measurement is 2.5-3 mm, the fetus is at risk for anomalies. If the NT measurement is >3mm, the risk of fetal abnormality is higher, suggesting a higher risk of possible chromosomal abnormality in the fetus. Pregnant women can consult their doctors to decide whether to undergo further non-invasive prenatal genetic testing, amniocentesis and other related tests to clarify the presence of fetal abnormalities. The fetus is already formed and the uterus is protruding from the pelvic cavity, so the pregnant woman does not need to hold her urine.