The normal value of HCY in pregnant women is usually less than 15 μmol/L, but depending on the condition of the pregnant woman, the value of HCY may be different, so this value can only be used as a reference. HCY levels in normal pregnant women are significantly lower than those in non-pregnant women, especially in middle and late pregnancy, which may be due to increased blood volume and blood dilution during pregnancy, increased fetal demand for essential amino acids, HCY hypermethylation, and increased fetal utilization of HCY. HCY is an important metabolic intermediate product of sulfur-containing amino acids in the body and may be an independent risk factor for the development of atherosclerosis and other It may be an independent risk factor for the development of cardiovascular diseases such as atherosclerosis. The level of HCY in serum is related to genetic factors, nutritional factors, estrogen levels and age. In addition, serum HCY levels in mid-pregnancy can be used as an indicator for early diagnosis of hypertensive disorders in pregnancy, which is particularly important for guiding early clinical prevention and timely treatment. Therefore, pregnant women should routinely monitor serum HCY levels during pregnancy and promptly supplement essential substances required for HCY metabolism, such as folic acid and vitamin B12. Ensuring smooth HCY metabolism and normal serum HCY levels may be an effective means to prevent the occurrence of hypertensive disorders during pregnancy.