The NT test requires the fetus to be in a median sagittal position with the fetal body in natural flexion, the fetal head and spine in a straight line during the measurement, and a sagittal section of the fetal long axis to be able to accurately measure the NT value. If the fetal position is not suitable for examination, and it is not possible to know the thickness of the posterior nuchal translucency layer and the nasal bone, intervention can be made by the following ways: 1. eating: pregnant women can eat fruits and sweets to enhance fetal movement and adjust the fetal position; 2. moving: pregnant women can slightly shake their abdomen or walk appropriately to stimulate the fetus to change its intrauterine position; 3. changing the examination method: NT examination usually chooses transabdominal ultrasound, if the fetal position is persistently unsatisfactory, vaginal ultrasound may also be considered. If the fetal position is not satisfactory, you can rest for 1-2 days before rechecking the NT after intervention by eating or activity. In addition, the fetal activity will be reduced when the pregnant woman is fasting or hungry, so she should not go to the hospital for examination on an empty stomach.