Nurk Eha, Tell Grethe S, Refsum Helga, Ueland Per M, Vollset Stein E
LOCUS for Homosysteine and Related Vitamins, Department of Public Health and Primary Health Care, University of Bergen, Norway.
Am J Med. 2004 Jul 1;117(1):26-31. doi: 10.1016/j.amjmed.2004.01.019.
Methylenetetrahydrofolate reductase (MTHFR) is involved in the metabolism of folate and homocysteine; a polymorphism in the MTHFR gene (677C-->T) has been associated with adverse outcomes of pregnancy. We studied whether two polymorphisms in the MTHFR gene (677C-->T and 1298A-->C) are associated with pregnancy complications, adverse outcomes, and birth defects.
MTHFR polymorphisms were determined in blood collected in 1992 and 1993 from 5883 women aged 40 to 42 years, and linked with 14,492 pregnancies in the same women recorded in the Medical Birth Registry of Norway from 1967 to 1996.
The 677TT genotype in mothers was associated with increased risk of placental abruption (odds ratio [OR] = 2.6; 95% confidence interval [CI]: 1.4 to 4.8) compared with the CC variant. The risk of intrauterine growth restriction increased with number of T alleles (P for trend = 0.04). Compared with the 1298AA variant, the CC variant was associated with a reduced risk of very low birth weight infants (OR = 0.4; 95% CI: 0.2 to 0.8). No significant associations were found between MTHFR polymorphisms and birth defects.
The maternal MTHFR 677C-->T polymorphism was a risk factor for placental abruption. The unexpected protective effect of the 1298A-->C polymorphism on very low birth weight needs further study.
亚甲基四氢叶酸还原酶（MTHFR）参与叶酸和同型半胱氨酸的代谢；MTHFR基因中的一种多态性（677C→T）与妊娠不良结局相关。我们研究了MTHFR基因中的两种多态性（677C→T和1298A→C）是否与妊娠并发症、不良结局及出生缺陷相关。
对1992年和1993年收集的5883名40至42岁女性血液中的MTHFR多态性进行测定，并将其与这些女性在1967年至1996年挪威医学出生登记处记录的14492次妊娠情况相联系。
与CC变异型相比，母亲的677TT基因型与胎盘早剥风险增加相关（比值比[OR]=2.6；95%置信区间[CI]：1.4至4.8）。宫内生长受限风险随T等位基因数量增加而升高（趋势P值=0.04）。与1298AA变异型相比，CC变异型与极低出生体重儿风险降低相关（OR=0.4；95%CI：0.2至0.8）。未发现MTHFR多态性与出生缺陷之间存在显著关联。
母亲的MTHFR 677C→T多态性是胎盘早剥的一个危险因素。1298A→C多态性对极低出生体重的意外保护作用需要进一步研究。
