| 1. |
- Altmae, Signe, et al.
(författare)
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Variations in folate pathway genes are associated with unexplained female infertility
- 2010
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Ingår i: Fertility and Sterility. - : Elsevier BV. - 0015-0282 .- 1556-5653. ; 94:1, s. 130-137
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate associations between folate-metabolizing gene variations, folate status, and unexplained female infertility. Design: An association study. Setting: Hospital-based IVF unit and university-affiliated reproductive research laboratories. Patient(s): Seventy-one female patients with unexplained infertility. Intervention(s): Blood samples for polymorphism genotyping and homocysteine, vitamin B12, and folate measurements. Main Outcome Measure(s): Allele and genotype frequencies of the following polymorphisms: 5,10-methylenetetra-hydrofolate reductase (MTHFR) 677C/T, 1298A/C, and 1793G/A, folate receptor 1 (FOLR1) 1314G/A, 1816delC, 1841G/A, and 1928C/T, transcobalamin II (TCN2) 776C/G, cystathionase (CTH) 1208G/T and solute carrier family 19, member 1 (SLC19A1) 80G/A, and concentrations of plasma homocysteine, vitamin B12, and serum folate. Result(s): MTHFR genotypes 677CT and 1793GA, as well as 1793 allele A were significantly more frequent among controls than in patients. The common MTHFR wild-type haplotype (677, 1298, 1793) CAG was less prevalent, whereas the rare haplotype CCA was more frequent in the general population than among infertility patients. The frequency of SLC19A1 80G/A genotypes differed significantly between controls and patients and the A allele was more common in the general population than in infertile women. Plasma homocysteine concentrations were influenced by CTH 1208G/T polymorphism among infertile women. Conclusion(s): Polymorphisms in folate pathway genes could be one reason for fertility complications in some women with unexplained infertility. (Fertil Steril (R) 2010;94:130-7. (C) 2010 by American Society for Reproductive Medicine.)
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| 2. |
- Laanpere, Margit, et al.
(författare)
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Folate-mediated one-carbon metabolism and its effect on female fertility and pregnancy viability
- 2010
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Ingår i: Nutrition reviews. - : Oxford University Press (OUP). - 0029-6643 .- 1753-4887. ; 68:2, s. 99-113
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Forskningsöversikt (refereegranskat)abstract
- This review summarizes current knowledge of the effect of folate-mediated one-carbon metabolism and related genetic variants on female fertility and pregnancy viability. Insufficient folate status disrupts DNA methylation and integrity and increases blood homocysteine levels. Elevated levels of follicular fluid homocysteine correlate with oocyte immaturity and poor early embryo quality, while methylenetetrahydrofolate reductase (MTHFR) gene variants are associated with lower ovarian reserves, diminished response to follicular stimulation, and reduced chance of live birth after in vitro fertilization. Embryos carrying multiple MTHFR variants appear to have a selective disadvantage; however, the heterozygousMTHFR 677CT genotype in the mother and fetus provides the greatest chance for a viable pregnancy and live birth, possibly due to a favorable balance in folate cofactor distribution between methyl donor and nucleotide synthesis. The results of previous studies clearly emphasize that imbalances in folate metabolism and related gene variants may impair female fecundity as well as compromise implantation and the chance of a live birth.
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| 3. |
- Laanpere, M, et al.
(författare)
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Folate-metabolizing gene variants and pregnancy outcome of IVF
- 2011
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Ingår i: Reproductive BioMedicine Online. - : Elsevier BV. - 1472-6483 .- 1472-6491. ; 22:6, s. 603-614
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Tidskriftsartikel (refereegranskat)abstract
- There is growing evidence that folate status and variation in folate-metabolizing genes are involved in female reproductive functions. This study evaluated the influence of maternal blood folate, vitamin B(12), homocysteine and 10 folate pathway gene variants on IVF outcome. Also, the prevalence of these polymorphisms was compared in 439 female IVF patients and 225 fertile controls. MTHFR 677 CT heterozygotes had a higher proportion of good-quality embryos and an increased chance of pregnancy. MTHFR 1793 GA heterozygosity was associated with a lower percentage of previously failed IVF treatments. Heterozygosity for FOLR1 1816 C/delC and 1841 G/A was associated with a raised risk of pregnancy loss. The CTH 1208 GT genotype was associated with an increased chance of pregnancy and a smaller number of previously failed IVF cycles and the genotype frequency was lower in IVF patients with three or more previously failed IVF treatments compared with fertile controls. SLC19A1 80 GA heterozygotes had a decreased number of previously failed IVF treatments and were more prevalent among fertile controls. In conclusion, polymorphisms in folate-metabolizing genes may affect ovarian stimulation and pregnancy outcome of IVF, and heterozygous individuals, rather than the wild-type homozygotes, appeared to have more favourable outcomes.
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| 4. |
- Murto, Tiina, et al.
(författare)
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Folic acid supplementation and IVF pregnancy outcome in women with unexplained infertility
- 2014
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Ingår i: Reproductive BioMedicine Online. - : Elsevier. - 1472-6483 .- 1472-6491. ; 28:6, s. 766-772
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Tidskriftsartikel (refereegranskat)abstract
- Folic acid supplements are commonly used by infertile women and lead to a positive folate status. However, the effect of folic acid supplements on pregnancy outcome in women with unexplained infertility has not been well investigated. This study evaluated folic acid supplement use and folate status in women with unexplained infertility in relation to pregnancy outcome. In addition, use of folic acid supplements and folate status were compared between women with unexplained infertility and fertile, nonpregnant control women. Women with unexplained infertility used significantly more folic acid supplements and had higher median total folic acid intake from supplements compared with fertile control women (both P < 0.001). Women with unexplained infertility also had significantly higher median plasma folate and lower median plasma homocysteine concentrations than fertile women (both P < 0.001), but folic acid supplementation or folate status were not related to pregnancy outcome in women with unexplained infertility. In conclusion, folic acid supplementation or good folate status did not have a positive effect on pregnancy outcome following infertility treatment in women with unexplained infertility.
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| 5. |
- Murto, Tiina, 1975-, et al.
(författare)
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Folic acid supplementation and methylenetetrahydrofolate reductase (MTHFR) gene variations in relation to IVF pregnancy outcome
- 2014
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 0001-6349 .- 1600-0412. ; 94:1, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To study folic acid intake, folate status and pregnancy outcome after infertility treatment in women with different infertility diagnoses in relation to methylenetetrahydrofolate reductase (MTHFR) 677C>T, 1298A>C and 1793G>A polymorphisms. Also the use of folic acid supplements, folate status and the frequency of different gene variations were studied in women undergoing infertility treatment and fertile women.DESIGN: Observational study.SETTING: University hospital.POPULATION: Women undergoing infertility treatment and healthy, fertile, non-pregnant women.METHODS: A questionnaire was used to assess general background data and use of dietary supplements. Blood samples were taken to determine plasma folate and homocysteine levels, and for genomic DNA extraction. A comparison of four studies was performed to assess pregnancy outcome in relation to MTHFR 677 TT vs. CC, and 1298 CC vs. AA polymorphisms.MAIN OUTCOME MEASURES: Folic acid supplement intake, and plasma folate, homocysteine and genomic assays.RESULTS: Women in the infertility group used significantly more folic acid supplements and had better folate status than fertile women, but pregnancy outcome after fertility treatment was not dependent on folic acid intake, folate status or MTHFR gene variations.CONCLUSION: High folic acid intakes and MTHFR gene variations seem not associated with helping women to achieve pregnancy during or after fertility treatment.
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