The C13 test can be done during pregnancy preparation and will not affect the pregnancy or the fetus; C13 is the simplest and most effective method to detect H. pylori infection without radiation. Precautions during pregnancy preparation are as follows: 1. Do not contact with radioactive substances, such as X-rays and microwaves, to avoid damage to the embryo. 2. Use medication under the guidance of a doctor and do not use medication privately to avoid embryonic dysplasia or pre-eclampsia. 3. Eat a light diet with balanced nutrition, eat more vegetables and fruits, do not eat spicy and stimulating food, and do not eat raw and cold food. 4. Take folic acid supplements to prevent neural tube abnormalities. 5. Proper activity to enhance body immunity. 6. Regular work and rest time, do not stay up late.