The time to do NT for embryo transfer is 11 to 13(+6) weeks after successful transfer. NT test at this stage can clearly see the fetal nuchal translucency as well as the nasal bone. NT, also known as posterior nuchal translucency thickness, is an important indicator for screening for fetal malformations in early pregnancy. Measuring the fetal nuchal translucency through nuchal translucency testing is not only an important risk measure for early Down’s syndrome screening, but also an important screening basis for other chromosomal disorders and non-chromosomal problems such as congenital heart disease. The NT test is an abdominal ultrasound, not a blood test, and you do not need to fast before the test, nor do you need to hold your urine. You can drink water or move around appropriately before the examination, which can stimulate the fetal activity and enable the fetus to take a more appropriate fetal orientation and be able to measure accurately. After the embryo transfer, you should pay attention to rest, keep a pleasant mood, if there are uncomfortable symptoms, you should go to the hospital in time for examination.