Why should I check for homocysteine ​​when trying to conceive? What should I do when it is too high?

Science Guide: Shenzhen Central Li Cuiyu, Department of Nutrition, Hospital


Everyone Maybe not very familiar

but it is related to cardiovascular and cerebrovascular diseases and

pregnancy success rate

Homocysteine Amino acid is a sulfur-containing amino acid isolated from bladder stones by Vincent Divino in 1931. In addition to being positively correlated with the incidence of cardiovascular and cerebrovascular diseases, hyperhomocysteinemia is also associated with recurrent miscarriage, threatened miscarriage, placental abruption, fetal growth restriction, fetal malformation, premature delivery, and pregnancy-induced hypertension. , gestational diabetes and other diseases are related to the success rate of assisted reproductive technology.

Ms. Wang came to the Nutrition Department of Shenzhen Hospital of Traditional Chinese Medicine in early August this year for pregnancy preparation Nutritional counseling, worrying about my homocysteine ​​level, the nutrition department conducted relevant examinations (vitamins that may be deficient related to elevated homocysteine, such as folic acid, vitamin B12, vitamin B2, vitamin B6, etc.), Nutrition therapy was also carried out. After two months of individualized supplementation, Ms. Wang’s homocysteine ​​level dropped to a relatively safe range.

Homocysteine ​​is a sulfur-containing amino acid, the product of demethylation of methionine, and is a recognized risk marker for cardiovascular and cerebrovascular diseases, neuropsychiatric diseases and birth defects at home and abroad thing. It is generally believed that the adult judgment reference range of homocysteine ​​is as follows:

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Normal range: 1-15μmol/L;

Target safety range: <6.3μmol/L;

Relative safety range: 6.3-10μmol/L;

Slightly high: 10- 15μmol/L;

mild hyperhomocysteinemia: 15-30μmol/L;

moderate hyperhomocysteinemia: 31-100μmol/L;

Severe hyperhomocysteinemia: >100μmol/L.

Pregnant women Children and children belong to special populations and should be lower than the reference value for adults. The median value of blood homocysteine ​​in Chinese adults is between 13 and 14 μmol/L, which is more than 30% higher than the relative safety range compared with 10 μmol/L, and more attention should be given to prevention and control.

Hyperhomocysteinemia It is a class of metabolic diseases that can be treated. Through comprehensive intervention such as diet and drugs, most of them have a better prognosis. In order to optimize the prevention and treatment strategy of hyperhomocysteinemia, different methods are used to treat hyperhomocysteinemia caused by different causes. In June this year, the Birth Defect Prevention and Molecular Genetics Branch of , Early Childhood Development Committee and other expert representatives jointly wrote and released the “Expert Consensus on the Diagnosis, Treatment and Prevention of Hyperhomocysteinemia”.

Hyperhomocysteinemia is a Common metabolic abnormalities have complex etiology, including genetic and non-genetic diseases, which can occur from fetuses to the elderly, and the overall prevalence rate of the population is as high as 5%.

Hereditary Hyperhomocysteinemia
Hereditary hyperhomocysteinemia is divided into two categories: enzyme deficiency and coenzyme deficiency:
  • The most common enzyme defects are cystathionase β-synthetase, methylenetetrahydrofolate reductase, and methionine adenosyltransferase defects, which manifest as simple hyperhomocysteinemia
  • The most common coenzyme deficiency is cobalamin and folic acid metabolism disorders, and cobalamin metabolism disorders can lead to methylmalonic acidemia Syndrome with hyperhomocysteinemia.

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Nonhereditary Hyperhomocysteinemia

Contributors to non-hereditary hyperhomocysteinemia include malnutrition , vegetarianism, partial eclipse, aging, smoking, long-term drinking, chronic gastrointestinal diseases, liver and gallbladder diseases, kidney diseases, malignant tumors, drugs (methotrexate, isoniazid, contraceptives, etc.), etc., see the table below for details.

The biochemical metabolism of patients with hyperhomocysteinemia caused by different etiologies is different, and it is necessary to pass medical history investigation, blood and urine metabolic analysis, Vitamin determination, genetic analysis and other tests for differential diagnosis.

Illnesses during pregnancy:

Homocysteine ​​causes gestational hypertension, gestational diabetes, placental vascular disease, and habitual abortion through mechanisms such as vascular endothelial injury, poor chorionic vascularization, and abnormal embryonic development Etc.

Homocysteine ​​is also an independent risk factor for neural tube defects, which directly affects the degree of neural tube closure and leads to fetal malformation. The decrease of homocysteine ​​level after pregnancy is helpful to Maintaining the integrity of maternal vascular endothelial cells and the elasticity of coronary arteries is important in regulating maternal vascular adaptation to pregnancy and varies with the first, second, and third trimesters.

Thus, isomorphic half Cystine value can be used as a routine indicator for pregnant women to assess the risk of pregnancy diseases and birth defects.

Studies have shown that when the homocysteine ​​level in early pregnancy > 7.53 μmol/L, When mid-term > 7.21 μmol/L and late > 8.32 μmol/L, the risk of pregnancy complications and adverse pregnancy outcomes increases significantly, so it is recommended to try to control homocysteine ​​<8 μmol/L during pregnancy preparation.
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High homocysteine ​​causes infertility by affecting sperm production and sperm function , the higher the Hcy level, the lower the sperm concentration and motility.

  • Heritable hyperhomocysteinemia has been included in my country’s “First List of Rare Diseases” and is a treatable genetic metabolic disease. Patients with different genetic diseases have different degrees of severity, with overlapping symptoms, signs, and abnormal biochemical metabolism. It is necessary to clarify the etiology and organ function for individualized and precise treatment.
  • Hyperhomocysteinemia caused by non-genetic factors, on the basis of etiological treatment, carry out healthy lifestyle intervention, balanced diet, supplement folic acid, cobalamin, vitamin B6, betaine as needed, and improve nutritional metabolism .


[1]. Li Dongxiao et al., Hyperhomocysteinemia Expert Consensus on Diagnosis, Treatment and Prevention. Journal of Rare Diseases, 2022. 29(06): Page 1-4.

[2]. Kong Juan, Gao Tongtype Expert consensus on diagnosis and treatment of cysteinemia. Electronic Journal of Tumor Metabolism and Nutrition, 2020. 7(03): Page 283-288.

[3]. Zhen Jingran, Chinese expert consensus on reproductive health and supplementation of multiple micronutrients. Chinese Journal of Practical Gynecology and Obstetrics, 2021. 37(04): Page 453-456.

[4] .Donglin Chen and Jian Xu, Research progress on homocysteine ​​and pregnancy-related diseases. Preventive Medicine, 2020. 32(02): Page 147-151.