Abstract: Objective To investigate the genotype distribution of the methylenetetrahydrofolate reductase （MTHFR） C677T essential for the folic acid biosynthetic pathway among Chinese Han pregnant women in Anhui province, so as to provide pregnant women with guidance of supplementing folic acid. Methods By mean of PCR- chip hybridization method, 484 samples collected from Anhui province were detected the genotype distributions and allele frequencies of MTHFR C677T, then, the results were compared with published data in other 9 provinces of China. Results In Anhui Han pregnant women population,the CC,TC,and TT genotypic frequencies of SNP C677T were 25.2 % ,49.2 % and 25.6 %,respectively．Significant different of genotypic frequencies have been observed between Anhui women population and Shandong, Sichuan, Yunnan and Hainan women population （P<0.05）. Conclusion The distributions of C677T in the MTHFR gene showed geographical variations. The polymorphisms of MTHFR may play a role in birth defects risk, thus, periconceptional folic acid supplementation and healthcare following gene polymorphism investigation may be a powerful measure to decrease congenital malformations.

Key words: Anhui province, Pregnant woman population, MTHFR, Gene polymorphism