George Lena, Mills James L, Johansson Anna L V, Nordmark Anna, Olander Bodil, Granath Fredrik, Cnattingius Sven
Department of Medical Epidemiology, Huddinge University Hospital, Karolinska Institutet, PO Box 281, SE-171 77 Stockholm, Sweden.
JAMA. 2002 Oct 16;288(15):1867-73. doi: 10.1001/jama.288.15.1867.
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.
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.
Risk of spontaneous abortion vs maternal plasma folate level.
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 (< or =2.19 ng/mL [< or =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 > or =6.17 ng/mL [> or =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).
Low plasma folate levels were associated with an increased risk of early spontaneous abortion.
据报道，叶酸缺乏和补充叶酸均会增加自然流产风险。然而，结果尚无定论，且并非所有研究都对叶酸进行了测定。
研究血浆叶酸水平与自然流产风险之间的关联。
设计、地点和研究对象：基于人群的配对病例对照研究，研究对象为1996年1月至1998年12月在瑞典乌普萨拉县的自然流产女性病例及对照女性。在妊娠6至12周时，对468例病例和921例对照进行了血浆叶酸测定。
自然流产风险与孕妇血浆叶酸水平的关系。
与血浆叶酸水平在2.20至3.95 ng/mL（5.0至8.9 nmol/L）之间的女性相比，叶酸水平低（≤2.19 ng/mL[≤4.9 nmol/L]）的女性自然流产风险增加（校正比值比[OR]为1.47；95%置信区间[CI]为1.01 - 2.
