Plasma folate levels and risk of spontaneous abortion.

Abstract

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 (< 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).

CONCLUSION:

Low plasma folate levels were associated with an increased risk of early spontaneous abortion.

• Authors: Lena George, James L Mills, Anna L V Johansson, Anna Nordmark, Bodil Olander, Fredrik Granath, Sven Cnattingius
• Journal: JAMA (JAMA) Vol. 288 Issue 15 Pg. 1867-73 (Oct 16 2002) ISSN: 0098-7484 [Print] United States
• PMID: 12377085 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Folic Acid

Topics

• Abortion, Spontaneous (blood, epidemiology, etiology)
• Case-Control Studies
• Dietary Supplements
• Female
• Fetal Diseases (genetics)
• Fetus (cytology)
• Folic Acid (blood)
• Folic Acid Deficiency (complications)
• Gestational Age
• Humans
• Karyotyping
• Logistic Models
• Male
• Pregnancy
• Pregnancy Trimester, First
• Risk Factors
• Sweden (epidemiology)