Colds in early pregnancy are caused by a decline in the immune function of women during early pregnancy. At the beginning of pregnancy, the fertilized egg is deposited in the uterine lining and starts to differentiate and develop, and the fetus is a homozygous semi-allograft. In order to tolerate and not reject the fetus, and to avoid the maternal immune system from attacking the fetus, the immune function will be decreased, resulting in the decrease of the maternal resistance to the external viruses, bacteria, and other pathogens, and therefore the situation of catching a cold in the early stage of pregnancy will occur. Early pregnancy fetus is in the sensitive period of differentiation and development, such as maternal cold, may have an adverse effect on the differentiation and development of cells, which may easily lead to miscarriage, fetal malformation, need to actively seek medical treatment. If a woman with a cold during early pregnancy needs to use medication, she should do so under the guidance of a medical professional, so as to avoid improper application of medication leading to adverse consequences.