Pre-conception examination precautions mainly include light diet, fasting, holding urine, do not wear metal clothing, etc.. 1. Light diet: the pre-pregnancy test should limit the intake of high protein and high fat foods, and limit alcohol consumption to avoid affecting the results of liver and kidney function. Eat a light diet and fast after twelve o’clock in the evening the day before the test. 2. Fasting: If you want to take blood test or do ultrasound of liver and gallbladder, you must fast. 3. Urine holding: If you are going to have an ultrasound examination of the bladder, uterine attachments, etc., you should hold your urine to ensure that your bladder is full and you cannot urinate. 4. Don’t wear metal clothes: When you are going to have an X-ray examination, don’t wear metal clothes and cotton underwear is recommended. If you are already pregnant, inform your doctor in time and be cautious about doing X-ray examination.