Multiple linear regression models of fetal NT and plasma trace element levels in primiparas and multiparas.

*p** pa Model adjusted for maternal age, pre-pregnancy BMI, medication and supplement use.b Model adjusted for maternal age, pre-pregnancy BMI, gestational weeks, medication and supplement use.Multiple linear regression models of fetal NT and plasma trace element levels in primiparas and multiparas.

模型a校正产妇年龄、孕前体重指数（Body Mass Index, BMI）、用药及补剂使用情况；模型b校正产妇年龄、孕前体重指数（Body Mass Index, BMI）、孕周、用药及补剂使用情况。本研究针对初产妇与经产妇群体，构建了胎儿颈项透明层（NT）与血浆微量元素水平的多元线性回归模型。