Ultrasound examination at 8 weeks of pregnancy reveals that the diameter of the yolk sac is large, which may be a case of embryonic dysplasia and requires dynamic review. The diameter of the yolk sac is usually 3~8 millimeters, if it is more than 10 millimeters, it is considered as an enlarged yolk sac. If the yolk sac is found to be oversized at 8 weeks of pregnancy, it is possible that the embryo is underdeveloped. If the fetal heart and buds are now visible, it is recommended to have an ultrasound review in one week. If the fetal heart is normal on ultrasound after one week, the enlarged yolk sac can be left untreated and the effect on the fetus may be less. However, if the ultrasound review after one week found that the fetal heart disappeared, this means that it has caused embryonic sterilizations, which need to be cleared in time for treatment. Specifically should authoritative hospital visits, under the guidance of a specialist to determine and treat.