The C677T methylenetetrahydrofolate reductase variant and third trimester obstetrical complications in women with unexplained elevations of maternal serum alpha-fetoprotein.
BACKGROUND
The C677T MTHFR variant has been associated with the same third trimester pregnancy complications as seen in women who have elevations of maternal serum alpha-fetoprotein (MSAFP). We hypothesized that these women with third trimester pregnancy complications and MSAFP elevations would have an increased frequency of the variant compared to an abnormal study control group (women with MSAFP elevations without pregnancy complications) as well as to normal population controls.


METHODS
Women who had unexplained elevations of MSAFP in pregnancy were ascertained retrospectively. The frequency of the C677T MTHFR variant among those women with unexplained elevations of MSAFP who had experienced later pregnancy complications was compared to that of women with unexplained elevations of MSAFP without complications as well as to that of the previously established Manitoba frequency.


RESULTS
Women who had complications of pregnancy and an unexplained MSAFP elevation had a higher allele frequency for the C677T MTHFR variant (q = 0.36,) compared to women with MSAFP elevations and normal pregnancy outcomes (q = 0.25, OR 1.73 95% CI 1.25-2.37, p = 0.03). The frequency was also higher than that of the population controls (q= 0.25, OR 1.70 95% CI 1.11-2.60, p = 0.007). The frequency in women with MSAFP elevations without pregnancy complications was not significantly different from that of the population controls (p = 0.41).


CONCLUSIONS
Women with unexplained elevations of MSAFP and who experience complications in later pregnancy are more likely to have one or two alleles of the C677T MTHFR variant.
Björklund
Natalie K
NK
Department of Biochemistry & Medical Genetics, University of Manitoba, Winnipeg, Canada. umbjork1@cc.UManitoba.CA
Evans
Jane A
JA
Greenberg
Cheryl R
CR
Seargeant
Lorne E
LE
Schneider
Carol E
CE
Chodirker
Bernard N
BN
D003596:Cytosine / Q000378:metabolism*; D005260:Female; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008350:Manitoba / Q000453:epidemiology; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D010865:Pilot Projects; D017354:Point Mutation / Q000235:genetics; D011247:Pregnancy / Q000097:blood*; D011248:Pregnancy Complications / Q000453:epidemiology; D011263:Pregnancy Trimester, Third / Q000235:genetics*; D011795:Surveys and Questionnaires; D013941:Thymine / Q000378:metabolism*; D000509:alpha-Fetoproteins / Q000378:metabolism*
D000509:alpha-Fetoproteins; D003596:Cytosine; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D013941:Thymine