Positive anticardiolipin antibodies may lead to fetal arrest. Positive antibodies are prone to the formation of microthrombi, which can affect the blood supply to the placenta and the growth and development of the fetus, and may lead to fetal arrest. Anti-cardiolipin antibodies are autoantibodies produced in the body against cardiolipin-binding proteins, a disorder of the patient’s autoimmune system. Positive anticardiolipin antibodies may indicate anticardiolipin syndrome, which is characterized by recurrent hypercoagulable states, thrombosis, thrombocytopenia, repeated miscarriages, and fetal arrest. If a woman has a positive anticardiolipin antibody that leads to fetal arrest, it is recommended that she go to the hospital for examination and targeted treatment.