Abstract: Abstract: Objective To investigate the relationship between genetic polymorphisms of folic metabolic enzymes and
male sperm abnormality or adverse pregnancy. Methods A total of 929 males of Han nationality treated in Gansu
Provincial Maternity and Child-Care Hospital from January 2017 to December 2017 were selected as the research objects.
The patients were divided into the dysspermia group (290 cases of sperm abnormality), adverse pregnancy group (198 cases
of unexplained adverse pregnancy) and control group (441 cases of healthy people without adverse pregnancy). Genotypes of
MTHFR C677T, A1298C and MTRR A66G sites were detected in three groups of patients. Results The genotype
frequencies of MTHFR C677 TT, MTRR A66 AG and GG were significantly higher in dysspermia group and adverse
pregnancy group than those of control group (P＜0.05). The genotype frequency of MTHFR A1298C CC was significantly
higher in adverse pregnancy group than that of control group (P＜0.05). Multivariate Logistic regression showed that MTHFR
C677 TT, MTRR A66 AG and GG genotypes were independent risk factors for sperm abnormality (P＜0.05). MTHFR C677
TT, MTHFR 1298 CC and MTRR A66 AG and GG genotypes were independent risk factors for adverse pregnancy (P＜0.05).
Conclusion The genetic polymorphisms of MTHFR C677T and MTRR A66G may contribute to male sperm abnormality
and adverse pregnancy. MTHFR C677 TT, MTRR A66 AG and GG may be independent risk factors for male sperm
abnormality and adverse pregnancy.

Key words: infertility,male, 5, 10- methyle- netetrahydrofolate reductase (FADH2), polymorphism,single nucleotide;
methionine synthase reductase, sperm abnormality, adverse pregnancy, genetic polymorphisms