Abstract:Objective To explore the distributions of 5, 10-methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms among pregnant women in Guiyang region, provide a theoretical basis of scientific supplementation of folic acid. Methods From January 2017 to June 2018, in Guizhou Provincial People′s Hospital, 2644 pregnant women in Guiyang region were selected, the genotype of MTHFR C677T was detected by PCR-fluorescence probing. The distribution of C677T gene polymorphisms among Han and the ethnic minority women in Guiyang were analyzed statistically, then the results were compared with data of Han women reported and other ethnic minorities women in other regions had been reported before. Results The frequencies of CC, CT and TT of MTHFR C677T genotypes were 37.8%, 48.3% and 13.9%, frequencies of C, T alleles were 61.9% and 38.1% of Han women in Guiyang region, these were compared with Miao women, the differences were statistically significant (P < 0.05), compared with women of Buyi, Dong and Tujia nationalities, the differences were statistically significant (P < 0.05), Compared with the Han women in Guiyang and the Han women in Jiangsu, Qionghai, Nanning, Huizhou, Xian, Ningxia, Yantai, Langfang, Changchun, Shangzhi, the differences were statistically significant (P < 0.05), no statistically differences between Guiyang and Chengdu, Kunming (P > 0.05). There were statistically significant differences between Miao women in Liuzhou, Dong women in Sanjiang, Li women in Sanya, Chaoxian women in Yanbian, the differences were statistically significant (P < 0.05), no statistically differences with Tujia women in Badong, Bai women in Dali, Hui women in Yinchuang(P > 0.05). Conclusion The distributions of MTHFR C677T genes polymorphisms among women of childbearing age in Guiyang are different in various minorities and areas, which have national specificity and regional specificity.