Stanford University School of Medicine, Stanford, California, USA.
Am J Perinatol. 2011 Dec;28(10):747-52. doi: 10.1055/s-0031-1280855. Epub 2011 Jun 16.
We investigated multiple sources of folate and folic acid to determine whether their periconceptional intakes were associated with preterm delivery. Studied were controls from the National Birth Defects Prevention Study delivered September 1998 to December 2005. Telephone interviews were conducted with 5952 (68% of eligible) mothers. Women were queried about intake of vitamin supplements in the 12 weeks before conception through delivery. A version of the Nurse's Health Study food frequency questionnaire was used to assess food sources. Eight percent of infants ( N = 487) were preterm (<37 weeks). Compared with women who began intake of supplements with folic acid before pregnancy, those who began any time during pregnancy had an ~20% lowered risk of preterm delivery. Lower dietary intakes showed a modest increased risk of preterm delivery: odds ratios were 1.44 (1.01 to 2.04) for lowest quartile intake of folate and 1.27 (0.95 to 1.69) for lowest quartile intake of folic acid compared with the highest. Findings suggest some evidence that folates influenced risks; however, an interpretation of results was also consistent with no association between intake of folates and preterm delivery.
我们研究了多种叶酸来源和叶酸，以确定它们在围孕期的摄入量是否与早产有关。本研究的对象是 1998 年 9 月至 2005 年 12 月期间参与美国国家出生缺陷预防研究的对照组母亲。通过电话对 5952 名（符合条件的 68%）母亲进行了访谈。调查了她们在受孕前 12 周和分娩期间维生素补充剂的摄入量。采用护士健康研究食物频率问卷的一个版本来评估食物来源。8%的婴儿（N=487）早产（<37 周）。与在怀孕前开始服用含叶酸补充剂的女性相比，在怀孕期间任何时候开始服用的女性早产风险降低约 20%。较低的膳食摄入量显示出早产风险的适度增加：与最高摄入量相比，最低四分位数的叶酸摄入量的比值比为 1.44（1.01 至 2.04），最低四分位数的叶酸摄入量的比值比为 1.27（0.95 至 1.69）。研究结果表明，有一些证据表明叶酸会影响风险；然而，结果的解释也与叶酸摄入量与早产之间没有关联一致。
