The normal value of the thickness of the posterior nuchal translucency is usually required to be less than 3mm. If the test reveals that it is greater than 3mm, there is a possibility of Down’s syndrome or chromosomal abnormalities, and this test is generally called NT test. When a woman is 11-13 weeks pregnant, she can go to the hospital for an ultrasound and NT test, which mainly reflects the specific condition of the embryo through the thickness of the zona pellucida. The thick zona pellucida may be a symptom of abnormality and needs to be checked again, and if there is an abnormality, it should be treated according to the actual situation. Pregnant women should pay attention to regular maternity checkups at the hospital, don’t have too much psychological pressure, and pay attention to a healthy diet, don’t eat spicy, fried and greasy food, and eat more fruits and vegetables.