Folic acid plays an important role in the growth and development of the human body. The human body cannot synthesize it and must be ingested from the outside; insufficient supplementation or poor utilization of folic acid will cause folic acid deficiency, leading to skin pigmentation, cheilitis, glossitis and clinical manifestations，such as hyperhomocysteinemia. Lack of folic acid in pregnant women can cause birth defects in the fetus, and pregnant women themselves can also have many undesirable symptoms.

It takes at least 12 weeks to reach an effective concentration of folic acid level in the mother's body, so it is usually recommended to supplement folic acid at least 3 months in advance.

Based on multiple fluorescent PCR-capillary electrophoresis, c.677 and c.1289 genetic loci on MTHFR gene and the c.66 genetic loci on MTRR gene that affect folate metabolism were detected. The risk of folate deficiency was calculated based on the genotyping information of the three

genetic loci，Providing folic acid supplement dosage advice and guiding the individualized folic acid supplement for pregnant couples.

• Pregnant couple.
  

• Pregnant women in the first trimester.
  

• Women with a history of abnormal gestation.
  

• Women with unexplained habitual abortion.
  

• Women with hyperhomocysteinemia and H-type hypertension.