MTHFR and fetal growth restriction: A systematic review and meta-analysis published by Bahrami et al. [34] in 2020 regarding the association between IUGR and MTHFR 677C>T polymorphism, which included eight studies with 687 cases of IUGR and 2336 controls, concluded that there is a significant association between MTHFR 677C>T polymorphism and IUGR with an OR 0.140, 95% CI 0.049–0.450 (p ≤ 0.001).