The following tests should be done at 31 weeks of pregnancy: 1. 2D ultrasound, the last systematic screening of the fetus for abnormalities and fetal growth and development in accordance with the gestational cycle. 2. Fetal ECG, to understand whether the fetus has arrhythmia. 3. Blood tests for routine blood, urine, liver function and ferritin, to understand whether the pregnant woman has anemia, thrombocytopenia, iron deficiency, proteinuria and ketone bodies in the urine, abnormal liver function, and whether bile acid is elevated. 4. If you have diabetes, you should also check glycosylated hemoglobin and blood glucose 2 hours after three meals to understand the pregnant woman’s blood glucose control. 4. If you have hypertension, diabetes, chronic kidney disease and other comorbidities during pregnancy, you should perform electronic fetal heart monitoring to understand the intrauterine condition of the fetus.