Methylenetetrahydrofolate reductase (MTHFR) C677T andA1298C variants do not affect ongoing pregnancy rates following in vitro fertilization.

Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, CA 94143, USA.
Human Reproduction (Impact Factor: 4.57). 03/2007; 22(2):450-6. DOI: 10.1093/humrep/del396
Source: PubMed


There is concern that IVF could compromise normal imprinting and methylation of DNA. Methylenetetrahydrofolate reductase (MTHFR) regulates the flow of folic acid-derived, one-carbon moieties for methylation and is critical to early embryonic development. Therefore, we hypothesized that common polymorphisms in MTHFR could associate with IVF outcome.
MTHFR C677T and A1298C polymorphism genotyping was performed on 374 subjects for this study, representing 197 couples undergoing IVF in a university setting from July 2005 to January 2006. Analysis of variance (ANOVA), chi-square and/or multivariate analyses were used to assess whether these polymorphisms are associated with embryo quality or with ongoing pregnancy or spontaneous abortion rates.
Allele frequencies for C677T ( p=0.67, q=0.33) and A1298C ( p=0.71, q=0.29) were in Hardy-Weinberg equilibrium. The C677T and A1298C variants, either alone or in combination, did not associate with embryo quality or short-term pregnancy outcome.
The common polymorphisms in MTHFR are not associated with embryo quality, as defined by cell number or fragmentation score, or with short-term pregnancy outcomes. Therefore, in our population in which women receive adequate folic acid, MTHFR genotypes are not informative in explaining IVF failure. Further studies, however, examining birth outcomes and the other enzymes in the folic acid pathway are warranted.

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Available from: Paolo Rinaudo, Feb 24, 2015
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    • "A previous study published by Dobson et al. in 2007 evaluated 197 couples undergoing assisted reproduction cycles and investigated the association between MTHFR polymorphisms C677T and A1298C in men and women in relation to laboratory results and pregnancy outcomes. The study found no association in any of the evaluations between the presence of polymorphism and laboratory results such as number and quality of embryos transferred and pregnancy rate in the assisted fertilization cycles performed (Dobson et al., 2007). Another study also associated the presence of the MTHFR polymorphism C677T with embryo quality by evaluating the genetic variants of folate metabolism and IVF outcomes in 439 women undergoing assisted fertilization cycles. "
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