If the carbon 14 test is performed in the early stages of pregnancy, it will have less effect on the fetus. But it needs to be done under the guidance of a doctor. Carbon 14 test can be performed when pregnant. Carbon 14 test mainly detects the presence of Helicobacter pylori infection in the body, which can prevent the occurrence of chronic gastritis, gastric cancer, gastric ulcer and other diseases. Carbon 14 test is relatively low in radiation to pregnant women, and will not affect the growth and development of the fetus in the early stages of pregnancy. However, it is important to note that the carbon 14 test should be used under the guidance of a doctor and treated accordingly. Carbon 14 test is an auxiliary means of examination and is usually not absorbed by the body. In addition, pregnant women should go to the hospital regularly for pregnancy checkups and closely observe the growth and development of the fetus.