When anti-cardiolipin antibodies are positive, pregnancy is generally not recommended, because pregnancy may affect fetal development, and in serious cases may lead to fetal malformation and fetal death, the specific hazards are as follows: 1. Affect fetal development: anti-cardiolipin antibodies mainly act on platelets and endothelial cells, which may affect the endothelial cells of the placental vessels, leading to the formation of thrombus in the placenta, thus affecting the normal blood circulation of the fetus and affecting fetal development; 2. Cause fetal malformation: most of the patients need to take hormone drugs for the treatment of primary disease, and the use of hormone drugs during pregnancy may affect fetal growth and development, resulting in miscarriage or fetal malformation; 3, leading to fetal death: anti-cardiolipin antibody positivity is common in systemic lupus erythematosus and other autoimmune diseases, and if serious autoimmune diseases occur, patients may have ischemic and hypoxic symptoms, leading to fetal miscarriage and death. In case of positive anti-cardiolipin antibodies after pregnancy, it is generally recommended to treat with subcutaneous injection of low-molecular heparin or oral treatment with small doses of aspirin as prescribed by the doctor, in addition, attention should be paid to strengthening maternity checkups and timely monitoring of the fetus.