van den Broek Nynke, Dou Lixia, Othman Mohammad, Neilson James P, Gates Simon, Gülmezoglu A Metin
Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK, L3 5QA.
Cochrane Database Syst Rev. 2010 Nov 10(11):CD008666. doi: 10.1002/14651858.CD008666.pub2.
The World Health Organization recommends routine vitamin A supplementation during pregnancy or lactation in areas with endemic vitamin A deficiency (where night blindness occurs), based on the expectation that supplementation will improve maternal and newborn outcomes including mortality, morbidity and prevention of anaemia or infection.
To review the effects of supplementation of vitamin A, or one of its derivatives, during pregnancy, alone or in combination with other vitamins and micronutrients, on maternal and newborn clinical outcomes.
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (15 July 2010).
All randomised or quasi-randomised trials, including cluster-randomised trials, evaluating the effect of vitamin A supplementation in pregnant women.
Two review authors independently assessed all studies for inclusion and resolved any disagreement through discussion with a third person. We used pre-prepared data extraction sheets.
We examined 88 reports of 31 trials, published between 1931 and 2010, for inclusion in this review. We included 16 trials, excluded 14, and one is awaiting assessment.Overall when trial results are pooled, Vitamin A supplementation does not affect the risk of maternal mortality (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.55 to 1.10, 3 studies, Nepal, Ghana,UK ), perinatal mortality, neonatal mortality, stillbirth, neonatal anaemia, preterm birth or the risk of having a low birthweight baby. Vitamin A supplementation reduces the risk of maternal night blindness (risk ratio (RR) 0.70, 95% CI 0.60 to 0.82, 1 trial Nepal). In vitamin A deficient populations and HIV-positive women, vitamin A supplementation reduces maternal anaemia (risk ratio (RR) 0.64, 95% confidence interval (CI) 0.43 to 0.94, 3 trials, Indonesia, Nepal,Tanzania ). There is evidence that vitamin A supplements may reduce maternal clinical infection (RR 0.37, 95% CI 0.18 to 0.77, 3 trials, South Africa, Nepal and UK).In HIV-positive women vitamin A supplementation given with other micronutrients was associated with fewer low birthweight babies (< 2.5 kg) in the supplemented group in one study (RR 0.67, CI 0.47 to 0.96).
AUTHORS' CONCLUSIONS: The pooled results of two large trials in Nepal and Ghana (with almost 95,000 women) do not currently suggest a role for antenatal vitamin A supplementation to reduce maternal or perinatal mortality. However the populations studied were probably different with regard to baseline vitamin A status and there were problems with follow-up of women. There is good evidence that antenatal vitamin A supplementation reduces maternal anaemia for women who live in areas where vitamin A deficiency is common or who are HIV-positive. In addition the available evidence suggests a reduction in maternal infection, but these data are not of a high quality.
世界卫生组织建议，在维生素A缺乏流行地区（即出现夜盲症的地区），孕期或哺乳期应常规补充维生素A，预期补充维生素A可改善孕产妇和新生儿结局，包括死亡率、发病率以及预防贫血或感染。
综述孕期单独补充维生素A或其衍生物之一，或与其他维生素和微量营养素联合补充，对孕产妇和新生儿临床结局的影响。
我们检索了Cochrane妊娠与分娩组试验注册库（2010年7月15日）。
所有评估孕妇补充维生素A效果的随机或半随机试验，包括整群随机试验。
两位综述作者独立评估所有研究是否纳入，并通过与第三人讨论解决任何分歧。我们使用预先准备好的数据提取表。
我们审查了1931年至2010年间发表的31项试验的88份报告，以纳入本综述。我们纳入了16项试验，排除了14项，1项正在等待评估。总体而言，汇总试验结果时，补充维生素A不影响孕产妇死亡风险（风险比（RR）0.78，95%置信区间（CI）0.55至1.10，3项研究，尼泊尔、加纳、英国）、围产期死亡率、新生儿死亡率、死产、新生儿贫血、早产或低体重儿风险。补充维生素A可降低孕产妇夜盲症风险（风险比（RR）0.70，95%CI 0.60至0.82，1项试验，尼泊尔）。在维生素A缺乏人群和HIV阳性女性中，补充维生素A可降低孕产妇贫血（风险比（RR）0.64，95%置信区间（CI）0.43至0.94，3项试验，印度尼西亚、尼泊尔、坦桑尼亚）。有证据表明，维生素A补充剂可能降低孕产妇临床感染（RR 0.37，95%CI 0.18至0.77，3项试验，南非、尼泊尔和英国）。在一项研究中，HIV阳性女性同时补充其他微量营养素时，补充组低体重儿（<2.5kg）较少（RR 0.67，CI 0.47至0.96）。
尼泊尔和加纳两项大型试验（近95000名女性）的汇总结果目前未表明产前补充维生素A可降低孕产妇或围产期死亡率。然而，所研究人群的基线维生素A状况可能不同，且女性随访存在问题。有充分证据表明，产前补充维生素A可降低维生素A缺乏常见地区或HIV阳性女性的孕产妇贫血。此外，现有证据表明可降低孕产妇感染，但这些数据质量不高。
