Shaw G M, Schaffer D, Velie E M, Morland K, Harris J A
California Birth Defects Monitoring Program, Emeryville 94608, USA.
Epidemiology. 1995 May;6(3):219-26. doi: 10.1097/00001648-199505000-00005.
With a case-control study, we investigated whether periconceptional intake of supplemental or dietary folate reduced the risk of having a neural tube defect (NTD)-affected pregnancy. Mothers of 549 (88% of eligible) cases and 540 (88%) controls were interviewed in person about vitamin supplements used in either the 3 months before or the 3 months after conception and also about usual diet in the 3 months before conception. Women with any use of a folic acid-containing vitamin in the 3 months before conception had a lower risk of having an NTD-affected pregnancy [odds ratio (OR) = 0.65; 95% confidence interval (CI) = 0.45-0.94]. ORs were similar for 3 levels (< 0.4, 0.4-0.9, and > 0.9 mg per day) of average daily intake of folic acid. Any level of use in the first 3 months after conception resulted in a lowered risk as well (OR = 0.60; 95% CI = 0.46-0.79). Reduced risks were less marked for Hispanics and were not observed among women who graduated from college. Modest reduced risks were noted among non-vitamin users whose estimated daily dietary intake of folate was more than 0.227 mg. We observed decreasing risk with increasing folate intake from combined dietary sources and vitamin supplements. A reduction in NTD risk associated with folate intake is consistent with other studies; however, the reduced risk may be particular to subsets of the population, primarily non-Hispanic women and women whose education does not exceed high school.
通过一项病例对照研究，我们调查了受孕前后补充叶酸或膳食叶酸的摄入量是否会降低胎儿患神经管缺陷（NTD）的风险。我们亲自访谈了549例（符合条件者的88%）病例的母亲和540例（88%）对照的母亲，询问她们在受孕前3个月或受孕后3个月使用的维生素补充剂，以及受孕前3个月的日常饮食情况。在受孕前3个月使用过任何含叶酸维生素的女性，其胎儿患NTD的风险较低[比值比（OR）=0.65；95%置信区间（CI）=0.45 - 0.94]。叶酸平均每日摄入量的3个水平（<0.4、0.4 - 0.9和>0.9毫克/天）的OR值相似。受孕后前3个月的任何使用水平也会降低风险（OR = 0.60；95% CI = 0.46 - 0.79）。西班牙裔女性的风险降低不太明显，在大学毕业的女性中未观察到风险降低。在估计每日膳食叶酸摄入量超过0.227毫克的非维生素使用者中，观察到风险适度降低。我们观察到，随着从膳食来源和维生素补充剂中摄入的叶酸增加，风险降低。与叶酸摄入相关的NTD风险降低与其他研究一致；然而，风险降低可能在特定人群亚组中尤为明显，主要是非西班牙裔女性和教育程度不超过高中的女性。
