The nt2.6mm malformation is not very likely, the normal nt value is below 2.5, this value just exceeds the normal range value so do not worry too much, the probability of malformation is less than 20%. nt value 2.6mm may also be the measurement error or fetal in the process of examination, lymphatic circulation and other problems caused by not necessarily belong to the abnormal, can be further related to the examination and then We can determine this after further tests. If you are worried about the health of the fetus, you can go to the hospital after a period of time for a non-invasive DHA test or an amniocentesis test, which can determine the development of the fetus. The nt test, which is usually performed at 11-13 weeks of pregnancy, is only an early method of measuring malformations and is not decisive.