Zeng Lingxia, Dibley Michael J, Cheng Yue, Dang Shaonong, Chang Suying, Kong Lingzhi, Yan Hong
Department of Public Health, Xi'an Jiaotong University College of Medicine, PO Box 46, Xi'an, Shaanxi 710061, China.
BMJ. 2008 Nov 7;337:a2001. doi: 10.1136/bmj.a2001.
To examine the impact of antenatal supplementation with multiple micronutrients or iron and folic acid compared with folic acid alone on birth weight, duration of gestation, and maternal haemoglobin concentration in the third trimester.
Cluster randomised double blind controlled trial.
Two rural counties in north west China.
5828 pregnant women and 4697 live births.
Villages were randomised for all pregnant women to take either daily folic acid (control), iron with folic acid, or multiple micronutrients with a recommended allowance of 15 vitamins and minerals.
Birth weight, length, and head circumference measured within 72 hours after delivery. Neonatal survival assessed at the six week follow-up visit.
Birth weight was 42 g (95% confidence interval 7 to 78 g) higher in the multiple micronutrients group compared with the folic acid group. Duration of gestation was 0.23 weeks (0.10 to 0.36 weeks) longer in the iron-folic acid group and 0.19 weeks (0.06 to 0.32 weeks) longer in the multiple micronutrients group. Iron-folic acid was associated with a significantly reduced risk of early preterm delivery (<34 weeks) (relative risk 0.50, 0.27 to 0.94, P=0.031). There was a significant increase in haemoglobin concentration in both iron-folic acid (5.0 g/l, 2.0 to 8.0 g/l, P=0.001) and multiple micronutrients (6.9 g/l, 4.1 to 9.6 g/l, P<0.001) groups compared with folic acid alone. In post hoc analyses there were no significant differences for perinatal mortality, but iron-folic acid was associated with a significantly reduced early neonatal mortality by 54% (relative risk 0.46, 0.21 to 0.98).
In rural populations in China antenatal supplementation with iron-folic acid was associated with longer gestation and a reduction in early neonatal mortality compared with folic acid. Multiple micronutrients were associated with modestly increased birth weight compared with folic acid, but, despite this weight gain, there was no significant reduction in early neonatal mortality. Pregnant women in developing countries need sufficient doses of iron in nutrient supplements to maximise reductions in neonatal mortality. Trial registration ISRCTN08850194.
研究孕期补充多种微量营养素或铁与叶酸，相较于单独补充叶酸，对出生体重、妊娠期时长以及孕晚期孕妇血红蛋白浓度的影响。
整群随机双盲对照试验。
中国西北部的两个乡村县。
5828名孕妇及4697例活产儿。
将村庄随机分组，所有孕妇分别每日服用叶酸（对照组）、铁与叶酸合剂或含15种维生素和矿物质推荐剂量的多种微量营养素。
分娩后72小时内测量出生体重、身长和头围。在六周随访时评估新生儿存活情况。
与叶酸组相比，多种微量营养素组的出生体重高42克（95%置信区间为7至78克）。铁与叶酸组的妊娠期长0.23周（0.10至0.36周），多种微量营养素组的妊娠期长0.19周（0.06至0.32周）。铁与叶酸组与早期早产（<34周）风险显著降低相关（相对风险0.50，0.27至0.94，P = 0.031）。与单独补充叶酸相比，铁与叶酸组（5.0克/升，2.0至8.0克/升，P = 0.001）和多种微量营养素组（6.9克/升，4.1至9.6克/升，P<0.001）的血红蛋白浓度均显著升高。事后分析显示围产期死亡率无显著差异，但铁与叶酸组与早期新生儿死亡率显著降低54%相关（相对风险0.46，0.21至0.98）。
在中国农村人口中，与单独补充叶酸相比，孕期补充铁与叶酸可使妊娠期延长，并降低早期新生儿死亡率。与叶酸相比，多种微量营养素与出生体重适度增加相关，但尽管有体重增加，早期新生儿死亡率并未显著降低。发展中国家的孕妇需要在营养补充剂中摄入足够剂量的铁，以最大程度降低新生儿死亡率。试验注册号ISRCTN08850194。
