NK cells are high, if you have to take heparin in order to preserve the fetus. NK cells kill earlier than other effector cells, is the body’s anti-tumor first line of defense cells, but if NK cells are high, it is easy to lead to infertility.NK high belongs to the immune disease, prone to spontaneous abortion, the embryo stops developing and other phenomena. NK cells express low molecular heparin receptor and so on on the surface, so by playing low molecular heparin can regulate the expression and function of NK cells, so as to reduce NK cell activity. Adverse reactions such as bleeding at different sites, skin rash, and elevated transaminases may occur during heparin use. The drug is contraindicated in patients with severe renal impairment, hemorrhagic cerebrovascular accident, and uncontrolled hypertension. Note that platelet counts should be performed during drug administration and periodically reviewed during treatment. If the patient appears NK cell high phenomenon, it is recommended to consult a doctor in time, under the guidance of the doctor, improve the relevant examination, clarify the cause of the disease, symptomatic treatment, avoid unauthorized use of drugs, so as not to cause adverse effects.