title: Genetic polymorphism of MTHFR C677T with preterm birth and low birth weight susceptibility: a meta-analysis.
abstract: OBJECTIVE
  This study aimed at clarifying the association of maternal and neonatal methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms with preterm birth (PTB) and low birth weight (LBW) susceptibility, respectively.
  
  
  METHODS
  A systematic search of Embase, Medline, China Biological Medicine Database (CBM), Chinese National Knowledge Infrastructure (CNKI), and Wanfang Database was performed before June, 2016. The frequencies of maternal and neonatal MTHFR C677T genotypes in the cases and controls and other information were extracted by two independent investigators. Odds ratios (ORs) with 95% confidence intervals (CIs) were adopted to estimate the relationships between MTHFR C677T polymorphisms and PTB as well as LBW by random or fixed effect models.
  
  
  RESULTS
  Twenty-five studies from 20 articles concerning maternal and neonatal MTHFR C677T gene polymorphism with PTB and LBW were included in this study. Maternal MTHFR C677T polymorphism was associated with PTB risk under allele contrast (T vs. C, OR = 1.36, 95% CI 1.02-1.81), homozygote (TT vs. CC, OR = 1.70, 95% CI 1.07-2.68), and recessive (TT vs. CT + CC, OR = 1.49, 95% CI 1.00-2.22) model, but not dominant or heterozygote model. Maternal MTHFR C677T polymorphism was also associated with LBW risk under allele contrast (OR = 1.69, 95% CI 1.25-2.28), homozygote (OR = 2.26, 95% CI 1.44-3.54), dominant (OR = 1.71, 95% CI 1.19-2.47), recessive (OR = 1.79, 95% CI 1.42-2.26) model, but not heterozygote model. No associations between neonatal MTHFR C677T polymorphism and PTB or LBW were found under all genetic models.
  
  
  CONCLUSIONS
  Identification of maternal MTHFR C677T mutation may play a key role for primary prevention of PTB as well as LBW and screening pregnant women of high risk in developing countries.
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, No. 44 Wenhuaxi Road, 250012, Jinan, China.
authors.forename: Han
authors.initials: H
authors.lastname: Wu
authors.affiliation: Jinan Maternity and Child Care Hospital, Jinan, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
authors.affiliation: Jinan Centers for Disease Control and Prevention, Jinan, China.
authors.forename: Xingyi
authors.initials: X
authors.lastname: Geng
authors.affiliation: Jinan Centers for Disease Control and Prevention, Jinan, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Jinan Centers for Disease Control and Prevention, Jinan, China.
authors.forename: Liangliang
authors.initials: L
authors.lastname: Cui
authors.affiliation: Centre for Health Management and Policy, Shandong University, Jinan, China.
authors.forename: Zhongchun
authors.initials: Z
authors.lastname: Gao
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, No. 44 Wenhuaxi Road, 250012, Jinan, China. bjiang@sdu.edu.cn.
authors.forename: Baofa
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of Epidemiology, School of Public Health, Shandong University, No. 44 Wenhuaxi Road, 250012, Jinan, China. yliping@sdu.edu.cn.
authors.forename: Liping
authors.initials: L
authors.lastname: Yang
mesh_terms: D000483:Alleles; D044466:Asian People / Q000235:genetics; D002681:China; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007230:Infant, Low Birth Weight; D016239:MEDLINE; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D016017:Odds Ratio; D011110:Polymorphism, Genetic / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011247:Pregnancy; D047928:Premature Birth / Q000235:genetics*
chemical_list: C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)
keywords: Low birth weight; Meta-analysis; Methylenetetrahydrofolate reductase; Polymorphism; Preterm birth