Background: The association between conventional folic acid supplement (FAS) in pregnancy and the occurrence of adverse pregnancy outcomes, newborn defects has been proven. However, recent researches have reported a weakened association. Based on the different maternal metabolism capability of folic acid, it's beneficial for clinicians to provide pregnant women with different doses of FAS, that's individualized FAS.
Subjects and methods: A total of 2,677 pregnant women in Dazu, Chongqing, China were recruited in this cohort study. 1,539 women volunteered to receive individualized FAS, in which FAS dose increased with the risk level of maternal genotype? specify MTHFR and MTRR (write in full then abbreviate bracket open and close) while 1,138 women received conventional FAS with unified FAS dose. Additionally, 1,964 pregnant women without FAS were retrospectively analyzed as the control. Finally, the incidence of adverse pregnancy outcomes and newborn defects were recorded.
Results: Based on the genotype of MTHFR and MTRR, women were identified as five risk levels of folic acid metabolism. The distributions of genotype and risk levels were not significantly different between FAS-individualized supplement group and FAS-unified supplement group. However, compared with control or FAS-unified supplement group, the incidence of spontaneous abortion, prolonged pregnancy, premature labor, fetal macrosomia and congenital heart disease were significantly decreased in FAS-individualized supplement group. In subgroup analysis, individualized FAS significantly improved pregnancy outcomes for women between 20-40 years old and inhibited the occurrence of newborn defects in both women of the first gestation and women of ≥2 gestations.
Conclusions: The application of individualized FAS based on gene polymorphisms was more effective in preventing adverse outcomes in the mother and child.
Keywords: Folic acid supplement; gene polymorphisms; newborn defects; pregnancy outcomes.