Relton Caroline L, Pearce Mark S, Parker Louise
Paediatric and Lifecourse Epidemiology Research Group, School of Clinical Medical Sciences (Child Health), Newcastle University, Sir James Spence Institute, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP, UK.
Br J Nutr. 2005 May;93(5):593-9. doi: 10.1079/bjn20041395.
The extent to which maternal folate and vitamin B12 modulate infant birth weight is unclear. The present study investigated mothers in early gestation (mean 11.5 (sd 5.8) weeks) and neonates, at delivery. Erythrocyte (RBC) folate (mothers: n 683; neonates: n 614) and vitamin B12 (mothers: n 534; neonates: n 614) were measured. Data on smoking habits were available for 44 % of pregnancies (n 443). The relationship between vitamin levels and birth weight standardized for gender and gestational age was investigated, using linear regression and adjusting for possible confounding variables (maternal age, parity). Results are presented as standardized regression coefficients (b). Increasing maternal age was associated with elevated RBC folate (b 0.11 (95 % CI 0.08, 0.15), P<0.001; n 674) and smoking was associated with a decrease in maternal RBC folate (b -1.38 (95 % CI -1.92, -0.86), P=0.001; n 319). Neonatal RBC folate was predicted by maternal RBC folate (b 0.08 (95 % CI 0.04, 0.11), P=0.001; n 315) and maternal vitamin B12 (b 0.08 (95 % CI 0.01, 0.16), P=0.02; n 252). Smoking influenced maternal vitamin B12 status (b -0.88 (95 % CI -1.49, -0.27), P=0.005; n 231). Using univariate regression, smoking significantly influenced infant birth weight (b -2.15 (95 % CI -3.24, -1.04), P<0.001; n 437). However, the effect of smoking on birth weight was statistically non-significant when considered in a multivariate regression model, leaving maternal RBC folate as the only significant predictor of birth weight (b 0.25 (95 % CI 0.08, 0.42), P=0.005; n 145). These findings suggest that maternal folate status is an important determinant of infant birth weight. The combined effects of smoking and reduced RBC status on birth weight require further investigation.
母体叶酸和维生素B12对婴儿出生体重的调节程度尚不清楚。本研究调查了妊娠早期（平均11.5（标准差5.8）周）的母亲及其分娩时的新生儿。测量了红细胞（RBC）叶酸水平（母亲：n = 683；新生儿：n = 614）和维生素B12水平（母亲：n = 534；新生儿：n = 614）。44%的妊娠（n = 443）有吸烟习惯的数据。使用线性回归并对可能的混杂变量（母亲年龄、产次）进行调整，研究了按性别和胎龄标准化后的维生素水平与出生体重之间的关系。结果以标准化回归系数（b）表示。母亲年龄增加与红细胞叶酸水平升高相关（b = 0.11（95%置信区间0.08，0.15），P<0.001；n = 674），吸烟与母亲红细胞叶酸水平降低相关（b = -1.38（95%置信区间-1.92，-0.86），P = 0.001；n = 319）。新生儿红细胞叶酸水平由母亲红细胞叶酸水平（b = 0.08（95%置信区间0.04，0.11），P = 0.001；n = 315）和母亲维生素B12水平（b = 0.08（95%置信区间0.01，0.16），P = 0.02；n = 252）预测。吸烟影响母亲的维生素B12状态（b = -0.88（95%置信区间-1.49，-0.27），P = 0.005；n = 231）。使用单变量回归分析，吸烟显著影响婴儿出生体重（b = -2.15（95%置信区间-3.24，-1.04），P<0.001；n = 437）。然而，在多变量回归模型中考虑时，吸烟对出生体重的影响在统计学上不显著，母亲红细胞叶酸水平是出生体重的唯一显著预测因素（b = 0.25（95%置信区间0.08，0.42），P = 0.005；n = 145）。这些发现表明，母体叶酸状态是婴儿出生体重的重要决定因素。吸烟和红细胞状态降低对出生体重的综合影响需要进一步研究。
