RT Journal
A1 George L, Mills JL, Johansson AV, et al
T1 PLasma folate levels and risk of spontaneous abortion
JF JAMA
JO JAMA
YR 2002
FD October 16
VO 288
IS 15
SP 1867
OP 1873
DO 10.1001/jama.288.15.1867
UL http://dx.doi.org/10.1001/jama.288.15.1867
AB Context 
                  Both folate deficiency and folic acid supplements have been reported
to increase the risk of spontaneous abortion. The results are inconclusive,
however, and measurements of folate have not been available in all studies.Objective 
                  To study the association between plasma folate levels and the risk of
spontaneous abortion.Design, Setting, and Population 
                  Population-based, matched, case-control study of case women with spontaneous
abortion and control women from January 1996 through December 1998 in Uppsala
County, Sweden. Plasma folate measurements were available for 468 cases and
921 controls at 6 to 12 gestational weeks.Main Outcome Measure 
                  Risk of spontaneous abortion vs maternal plasma folate level.Results 
                  Compared with women with plasma folate levels between 2.20 and 3.95
ng/mL (5.0 and 8.9 nmol/L), women with low (≤2.19 ng/mL [≤4.9 nmol/L])
folate levels were at increased risk of spontaneous abortion (adjusted odds
ratio [OR], 1.47; 95% confidence interval [CI], 1.01-2.14), whereas women
with higher folate levels (3.96-6.16 ng/mL [9.0-13.9 nmol/L] and ≥6.17
ng/mL [≥14.0 nmol/L]) showed no increased risk of spontaneous abortion
(OR, 0.84; 95% CI, 0.59-1.20; and OR, 0.74; 95% CI, 0.47-1.16, respectively).
Low folate levels were associated with a significantly increased risk when
the fetal karyotype was abnormal (OR, 1.95; 95% CI, 1.09-3.48) but not when
the fetal karyotype was normal (OR, 1.11; 95% CI, 0.55-2.24) or unknown (OR,
1.45; 95% CI, 0.90-2.33).Conclusion 
                  Low plasma folate levels were associated with an increased risk of early
spontaneous abortion.