C677T polymorphism increases the risk of early spontaneous abortion

PURPOSE: To investigate the relationship of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in male population having spouses with early spontaneous abortion. METHODS: A total of 345 males whose spouses had at least one early spontaneous abortion were included in the study group, and 145 males who planned to have a second child were included in the control group. Semen was collected in a sterile cup by masturbation. After liquefaction, the sperm concentration and forward motility sperm rate (PR) were obtained. The genomic DNA was extracted from peripheral vein, followed by MTHFR C677T polymorphism detection through PCR-gold magnetic nanoparticle chromatography. RESULTS: The numbers of alleles and genotypes of MTHFR in the case group were 303 (C), 387 (T), 64 (CC), 175 (CT), and 106 (TT) cases, respectively. The numbers of allele and genotype of MTHFR in the control group were 167 (C), 123 (T), 145 (CC), 65 (CT), and 29 (TT) cases. There were significant differences in the distribution frequency of genotypes (χ(2) = 17.005, P = 0.000) and alleles (χ(2) = 15.295, P = 0.000) between the two groups. For cases with more spontaneous abortion, more cases had CT and TT phenotypes. Participants with genotype CT had the highest sperm concentration and PR in both groups (P < 0.05). CONCLUSIONS: MTHFR could affect sperm DNA integrity through affecting DNA methylation, which led to an increase in the rate of early spontaneous abortion in spouses. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10815-019-01500-2) contains supplementary material, which is available to authorized users.