title: Association between maternal, fetal and paternal MTHFR gene C677T and A1298C polymorphisms and risk of recurrent pregnancy loss: a comprehensive evaluation.
abstract: OBJECTIVE
  Numerous studies have investigated the associations between methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C polymorphisms and risk of recurrent pregnancy loss (RPL); however, the results remain controversial. The aim of this study is to drive a more precise estimation of association between MTHFR gene polymorphisms and risk of RPL.
  
  
  METHODS
  We searched PubMed, EMBASE, Cochrane library, Web of Science and China Knowledge Resource Integrated Database for papers on MTHFR gene C677T and A1298C polymorphisms and RPL risk. The pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were used to assess the strength of association in the homozygous model, heterozygous model, dominant model, recessive model and an additive model. The software STATA (Version 13.0) was used for statistical analysis.
  
  
  RESULTS
  Overall, 57 articles were included in the final meta-analysis. In maternal group the MTHFR C677T polymorphism showed pooled odds ratios for the homozygous comparison [OR = 2.285, 95 % CI (1.702, 3.067)] and the MTHFR A1298C polymorphism showed pooled odds ratios for recessive model [OR = 1.594, 95 % CI (1.136, 2.238)]. In fetal group the MTHFR C677T polymorphism showed pooled odds ratios for dominant model [OR = 1.037, 95 % CI (0.567, 1.894)] and the MTHFR A1298C polymorphism showed pooled odds ratios for dominant model [OR = 1.495, 95 % CI (1.102, 2.026)].
  
  
  CONCLUSIONS
  In summary, the results of our meta-analysis indicate that maternal and paternal MTHFR gene C677T and A1298C polymorphisms are associated with RPL. We also observed a significant association between fetal MTHFR A1298C polymorphism and RPL but not C677T.
authors.affiliation: West China Hospital, Sichuan University, No.37, GuoXueXiang, Chengdu, 610041, Sichuan, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.affiliation: West China Medical School, Sichuan University, Chengdu, China.
authors.forename: Yunyao
authors.initials: Y
authors.lastname: Luo
authors.affiliation: West China Medical School, Sichuan University, Chengdu, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
authors.affiliation: West China Medical School, Sichuan University, Chengdu, China.
authors.forename: Yidan
authors.initials: Y
authors.lastname: Tang
authors.affiliation: West China Medical School, Sichuan University, Chengdu, China.
authors.forename: Lang
authors.initials: L
authors.lastname: Xiong
authors.affiliation: West China Hospital, Sichuan University, No.37, GuoXueXiang, Chengdu, 610041, Sichuan, China.
authors.forename: MangMang
authors.initials: M
authors.lastname: Xu
authors.affiliation: Jiangxi Medical School, Nanchang University, Nanchang, China.
authors.forename: XuDong
authors.initials: X
authors.lastname: Rao
authors.affiliation: West China Hospital, Sichuan University, No.37, GuoXueXiang, Chengdu, 610041, Sichuan, China. liuhao6304@hotmail.com.
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
mesh_terms: D000026:Abortion, Habitual / Q000235:genetics*; D000483:Alleles; D002681:China; D005190:Family; D005220:Fathers; D005260:Female; D005333:Fetus / Q000201:enzymology; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D009035:Mothers; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011247:Pregnancy; D012306:Risk
chemical_list: D042965:Methylenetetrahydrofolate Reductase (NADPH2)
keywords: A1298C; C677T; MTHFR; Meta-analysis; Polymorphisms; Recurrent pregnancy loss