MTRR and fetal growth restriction: Padmanabhan et al. (2013) demonstrated that mutation of the mouse folate metabolism gene Mtrr in maternal grandparents was sufficient to cause defects including intrauterine growth restriction and congenital malformations in their wild-type grandoffspring. Therefore, whether maternal MTHFR polymorphism has an impact on the postnatal health of offspring or the health of the grandoffspring is worth further exploration.