Shaw G M, Velie E M, Schaffer D
March of Dimes Birth Defects Foundation, California Birth Defects Monitoring Program, Emeryville, CA 94608, USA.
JAMA. 1996 Apr 10;275(14):1093-6. doi: 10.1001/jama.1996.03530380035028.
To investigate the risk for neural tube defect (NTD)-affected pregnancies among obese women (ie, women with a body mass index [BMI] > 29kg/m2) compared with women of average prepregnancy weight.
Population-based case-control study.
All hospitals in 55 of 58 counties in California.
In-person interviews were conducted with mothers of 538 (88% of eligible) NTD cases (including fetuses and infants electively terminated, stillborn, or born alive) and with mothers of 539 nonmalformed controls (88%) within an average of 5 months from the term delivery date.
The risk of an NTD-affected pregnancy among obese women.
Compared with women whose BMI was less than or equal to 29 kg/m2, an increased risk for NTD-affected pregnancy was observed among obese women (odds ratio, 1.9; 95% confidence interval, 1.3 to 2.9). The increased risk was not attributable to maternal nonuse of a vitamin containing folic acid, diabetes, use of diet pills, lower dietary folate intake, or an NTD-pregnancy history. Adjustment for maternal age, education, gravidity, use of vitamins, and use of alcohol did not change the odds ratio. The risk associated with maternal obesity was greater for spina bifida and for other less prevalent NTDs than for anencephaly.
Because as many as 10% of women may be obese periconceptionally, the observed twofold increased risk is relevant to the population burden of NTDs.
调查肥胖女性（即体重指数[BMI]＞29kg/m²的女性）与孕前体重正常的女性相比，发生神经管缺陷（NTD）妊娠的风险。
基于人群的病例对照研究。
加利福尼亚州58个县中55个县的所有医院。
对538例（占符合条件者的88%）NTD病例（包括选择性终止妊娠的胎儿和婴儿、死产儿或活产儿）的母亲以及539例非畸形对照（88%）的母亲进行了面对面访谈，访谈时间平均在足月分娩日期后的5个月内。
肥胖女性发生NTD妊娠的风险。
与BMI小于或等于29kg/m²的女性相比，肥胖女性发生NTD妊娠的风险增加（比值比为1.9；95%置信区间为1.3至2.9）。风险增加并非归因于母亲未使用含叶酸的维生素、糖尿病、使用减肥药、膳食叶酸摄入量较低或有NTD妊娠史。对母亲年龄、教育程度、妊娠次数、维生素使用情况和饮酒情况进行调整后，比值比未发生变化。与脊柱裂和其他不太常见的NTD相比，母亲肥胖与无脑儿相关的风险更大。
由于多达10%的女性在受孕前后可能肥胖，因此观察到的风险增加两倍与NTD的人群负担相关。
