Chen Ling-Wei, Lim Ai Lin, Colega Marjorelee, Tint Mya-Thway, Aris Izzuddin M, Tan Chuen Seng, Chong Yap-Seng, Gluckman Peter D, Godfrey Keith M, Kwek Kenneth, Saw Seang-Mei, Yap Fabian, Lee Yung Seng, Chong Mary Foong-Fong, van Dam Rob M
Saw Swee Hock School of Public Health.
Singapore Institute for Clinical Sciences, A*STAR, Singapore.
J Nutr. 2015 Jan;145(1):113-20. doi: 10.3945/jn.114.196352. Epub 2014 Nov 12.
Maternal folate, vitamin B-12, and vitamin B-6 concentrations during pregnancy have been shown to influence birth outcomes, but the evidence is inconclusive.
We aimed to examine the associations of maternal B-vitamin status with gestational age, birth weight, and length in a birth cohort study in Singapore.
Maternal blood samples (n = 999) collected during weeks 26-28 of gestation were assayed for plasma folate, vitamin B-12, and vitamin B-6 concentrations. Birth weight and gestational age data were obtained from hospital records, and other anthropometric variables were measured within 72 h after birth. Relations between B-vitamin status and birth outcomes were assessed by linear or logistic regression with adjustment for potential confounders.
Median (IQR) plasma concentrations were 34.4 (24.5-44.6) nmol/L for folate, 209 (167-258) pmol/L for vitamin B-12, and 61.8 (25.9-113) nmol/L for vitamin B-6. We found that higher plasma folate concentrations were associated with a longer gestational age (0.12 wk per SD increase in folate; 95% CI: 0.02, 0.21) and tended to be associated with lower risk of all preterm birth (delivery at <37 wk of gestation; OR: 0.79; 95% CI: 0.63, 1.00) and spontaneous preterm birth (OR: 0.76; 95% CI: 0.56, 1.04). Overall, concentrations of maternal folate, vitamin B-12, and vitamin B-6 were not independently associated with birth weight or being born small for gestational age (SGA; birth weight <10th percentile for gestational age).
Higher maternal folate concentrations during late pregnancy were associated with longer gestational age and tended to be associated with a lower risk of preterm birth in this multiethnic Asian population. In contrast, the results of our study suggested little or no benefit of higher folate concentrations for reducing the risk of SGA or of higher vitamin B-6 and vitamin B-12 concentrations for reducing the risk of preterm birth or SGA.
孕期母体叶酸、维生素B-12和维生素B-6浓度已被证明会影响出生结局，但证据尚无定论。
在新加坡的一项出生队列研究中，我们旨在研究母体B族维生素状态与胎龄、出生体重和身长之间的关联。
对妊娠26 - 28周期间采集的母体血样（n = 999）检测血浆叶酸、维生素B-12和维生素B-6浓度。出生体重和胎龄数据从医院记录中获取，其他人体测量变量在出生后72小时内测量。通过线性或逻辑回归评估B族维生素状态与出生结局之间的关系，并对潜在混杂因素进行调整。
叶酸的血浆浓度中位数（IQR）为34.4（24.5 - 44.6）nmol/L，维生素B-12为209（167 - 258）pmol/L，维生素B-6为61.8（25.9 - 113）nmol/L。我们发现，较高的血浆叶酸浓度与较长的胎龄相关（叶酸每增加一个标准差，胎龄增加0.12周；95%CI：0.02，0.21），并且倾向于与所有早产（妊娠<37周分娩）风险降低相关（OR：0.79；95%CI：0.63，1.00）以及自发早产风险降低相关（OR：0.76；95%CI：0.56，1.04）。总体而言，母体叶酸、维生素B-12和维生素B-6浓度与出生体重或小于胎龄儿（SGA；出生体重低于胎龄的第10百分位数）并无独立关联。
在这个多民族亚洲人群中，妊娠晚期母体叶酸浓度较高与较长的胎龄相关，并且倾向于与较低的早产风险相关。相比之下，我们的研究结果表明，较高的叶酸浓度对降低SGA风险几乎没有益处，较高的维生素B-6和维生素B-12浓度对降低早产或SGA风险也几乎没有益处。
