Objective:To analyze the relationship of the embryonic development termination and the gene polymorphism of MTHFR and MTRR. Methods:MTHFRC677T

A1298 C and MTRRA66 G genotypes were analyzed by quantitative PCR in 90 women with embryonic stop fertility history(case group)and 99 normal pregnant women(control group). The characteristics of distribution were analyzed bystatistical software. Results:In case group

possibilities of MTHFRC677 T TT(puremutant

41 samples)

CT(heterozy gousmutant

55 samples)

CC(wild type

17 samples)genotypes were 45.6%

35.6%

18.8% respectively

comparing with 6.1%

55.5%

38.4%in control group. The results showed obvious difference in genortypes of TT

CT

and CC(χ2TT=39.358

PTT=0.000

χ2CT=7.591

PCT=0.006

χ2cc=8.684

PCC=0.003). When A1298 C mutated alone

the frequencies of A allele in case group and control group were 87.2% and 86.9%;the frequencies of C allele in case group and control group were 12.8% and 13.1%;there was no significant difference between them(χ2=0.010

P=0.919). There was only CT+AC when MTHFRA1298 C mutated in collaboration with MTHFRC677T;the frequencies of CT+AC homozygote in case group and control group were 14.4% and 4.00%(χ2=6.234

P=0.013). The comparison of the MTRRA66 G polymorphism between case group and control group:Chi-square values of AA

AG+GG

allele A were 4.78

11.343

7.846(P values were0.029

0.001

0.005). Conclusion:Single gene mutation of MTHFRC677 T and MTRRA66 G gene locus can easily lead to embryonic development termination. The mutation of MTHFR1298A-C can not induce embryonic development termination

but it may become a risk factor for embryonic development termination when it occurs with the mutation of 677C-T.