目的:探讨亚甲基四氢叶酸还原酶基因(MTHFR)多态性(C677T)与高同型半胱氨酸(Hcy)血症以及复发性流产之间的关系。方法:采用前瞻性病例对照研究方法,收集71例复发性自然流产患者为病例组,另征集同期58例有正常妊娠史者为对照组,利用PCR-RFLP方法研究MTHFR基因多态性(C677T);同时应用酶法测定血清同型半胱氨酸水平;并随访病例组的妊娠结局。结果:①MTHFR基因677位点的3种基因型在病例组和对照组分布分别为CC:14.1%vs 43.1%、CT:49.3%vs 25.9%、TT:36.6%vs 31.0%,组间比较有极显著统计学差异(χ2=14.7,df=2,P=0.001);其中CC基因型在病例组显著降低(P=0.000,OR=0.216,95%CI:0.093-0.505);T等位基因分布在病例组显著升高(61.3%vs 38.7%,P=0.006)。②129例研究对象中TT基因型血同型半胱氨酸水平显著升高(P=0.000):TT为19.0±9.5 nmol/L、CC为13.1±6.2 nmol/L、CT为11.7±4.0 nmol/L,病例组和对照组高Hcy水平组间无统计学差异(P>0.05)。③病例组中有38.0%(27/71)为高Hcy血症,叶酸治疗有效。结论:MTHFR基因多态性(C677T)与复发性流产有关;MTHFR基因TT型与高Hcy血症有关;叶酸可用于治疗高Hcy血症且有助于改善下次妊娠结局。 Objective: To investigate the relationship between methylenetetrahydrofolate reductase gene (MTHFR) polymorphism (C677T) and hyperhomocysteinemia and recurrent spontaneous abortion. Methods: A prospective case-control study was conducted in 71 patients with recurrent spontaneous abortion and 58 patients with normal pregnancy during the same period were enrolled as control group. MTHFR gene polymorphism (C677T) was detected by PCR-RFLP. At the same time, serum homocysteine ​​level was measured by enzymatic method. Pregnancy outcome of case group was followed up. Results: (1) The genotypes of 677 loci in MTHFR gene were 14.1% vs 43.1% in CC and 49.3% in CT, respectively, and 25.9% in TT, with a TT: 36.6% vs 31.0% (P = 0.000, OR = 0.216, 95% CI: 0.093-0.505). The distribution of T allele was significantly higher than that in the control group (χ2 = 14.7, df = In the case group was significantly higher (61.3% vs 38.7%, P = 0.006). ② The plasma level of homocysteine ​​in TT genotype was significantly increased in 129 subjects (P = 0.000): TT was 19.0 ± 9.5 nmol / L, CC was 13.1 ± 6.2 nmol / L and CT was 11.7 ± 4.0 nmol / L There was no significant difference between high Hcy group and control group (P> 0.05). ③ In the case group, 38.0% (27/71) were Hcy hyperlipidemia and folic acid was effective. CONCLUSIONS: MTHFR gene polymorphism (C677T) is associated with recurrent spontaneous abortion; the MTHFR TT genotype is associated with hyperhomocysteinemia; and folic acid may be useful in the treatment of hyperhomocysteinemia and may improve outcome in the next pregnancy.