Evaluation of association between methylenetetrahydrofolate reductase and azoospermia: A meta-analysis

Background:Infertility affects childbearing age couples all over the world. One of the important reasons for infertility is genetic factors. Our study evaluated the association between methylenetetrahydrofolate reductase (MTHFR) and azoospermia.Methods:Multiple databases like MEDLINE, EMBASE, Cochrane library, and China journal full-text database were used to search for relevant studies, and full-text articles involved in the evaluation of MTHFR and azoospermia. The results were evaluated using STATA 12.0. Heterogeneity analysis, sensitivity analysis, and bias analysis were also performed on the data.Results:Thirteen related studies eventually met the inclusion criteria. Significant association between C677T polymorphism and azoospermia (relative risk RR] = 0.94 0.90, 0.99], I² = 60.9%, P = .002), and between A1298C polymorphism and azoospermia (RR = 0.98 0.94, 1.02], I² = 56.3%, P = .011) was observed. Meanwhile, in subgroup analysis, Caucasians had higher risk than Mongolians in association between MTHFR and azoospermia.Conclusion:There was association between MTHFR polymorphism and azoospermia. Caucasian populations had higher risk than Mongolian populations in association between MTHFR and azoospermia.