Fetal development to the third trimester, ultrasound examination of the NT is not able to determine the sex of the boy or girl.NT is the abbreviation of the fetal nuchal translucency, refers to the thickness of the fetal nuchal translucency subcutaneous tissue fluid accumulation, usually in the 13th week of pregnancy about the examination.The normal value of the NT is less than 3mm, if greater than 3mm, we should consider the possibility of fetal Down’s syndrome, then it is recommended that pregnant mothers to do amniocentesis If the normal value of NT is less than 3mm, it should be considered that the fetus may have Down’s Syndrome. The NT test is only to rule out the development of the fetus, it cannot identify the sex of the fetus. Boys and girls are the same, do not be sexist, as long as there is no abnormality in the development of the fetus, healthy and safe growth is very good.