Overall, the results revealed no association between the MTHFR A1298C polymorphism and Chinese male infertility risk in the allele model (C vs. A: OR = 1.22, 95%CI = 0.97–1.53, I2 = 0), dominant model (CC + AC vs. AA: OR = 1.27, 95%CI = 0.98–1.65, I2 = 0), additive model (CC vs. AA: OR = 1.34, 95%CI = 0.66–2.71, I2 = 0) or recessive model (CC vs. AC+AA: OR = 1.44, 95%CI = 0.72–2.88, I2 = 9) (Figs 2–5). Here, MTHFR is linked to male infertility.