Wiysonge Charles Shey, Shey Muki, Kongnyuy Eugene J, Sterne Jonathan Ac, Brocklehurst Peter
School of Child and Adolescent Health, University of Cape Town, Institute of Infectious Disease and Molecular Medicine, Anzio Road, Observatory, Cape Town, South Africa, 7925.
Cochrane Database Syst Rev. 2011 Jan 19(1):CD003648. doi: 10.1002/14651858.CD003648.pub3.
Observational studies of pregnant women in sub-Saharan Africa have shown that low serum vitamin A levels are associated with an increased risk of mother-to-child transmission (MTCT) of HIV. Vitamin A is cheap and easily provided through existing health services in low-income settings. It is thus important to determine the effect of routine supplementation of HIV positive pregnant or breastfeeding women with this vitamin on the risk of MTCT of HIV, which currently results in more than 1000 new HIV infections each day world-wide.
We aimed to assess the effect of antenatal and or postpartum vitamin A supplementation on the risk of MTCT of HIV as well as infant and maternal mortality and morbidity.
In June 2010 we searched the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, AIDS Education Global Information System, and WHO International Clinical Trials Registry Platform; and checked reference lists of identified articles for any studies published after the earlier version of this review was updated in 2008.
We selected randomised controlled trials conducted in any setting that compared vitamin A supplementation with placebo in known HIV-infected pregnant or breastfeeding women.
At least two authors independently assessed trial eligibility and quality and extracted data. We calculated relative risks (RR) or mean differences (MD), with their 95% confidence intervals (CI) for each study. We conducted meta-analysis using a fixed-effects method (when there was no significant heterogeneity between study results, i.e. P>0.1) or the random-effects method (when there was significant heterogeneity), and report the Higgins' statistic for all pooled effect measures.
Five randomised controlled trials which enrolled 7,528 HIV-infected women (either during pregnancy or the immediate postpartum period) met our inclusion criteria. These trials were conducted in Malawi, South Africa, Tanzania, and Zimbabwe between 1995 and 2005. We combined the results of these trials and found no evidence that vitamin A supplementation has an effect on the risk of MTCT of HIV (4 trials, 6517 women: RR 1.04, 95% CI 0.87 to 1.24; I(2)=68%). However, antenatal vitamin A supplementation significantly improved birth weight (3 trials, 1809 women: MD 89.78, 95%CI 84.73 to 94.83; I(2)=33.0%), but there was no evidence of an effect on preterm births (3 trials, 2110 women: RR 0.88, 95%CI 0.65 to 1.19; I(2)=58.1%), stillbirths (4 trials, 2855 women: RR 0.99, 95%CI 0.68 to 1.43; I(2)=0%), deaths by 24 months (2 trials, 1635 women: RR 1.03, 95%CI 0.88 to 1.20; I(2)=0%), postpartum CD4 levels (1 trial, 727 women: MD -4.00, 95% CI -51.06 to 43.06), and maternal death ( 1 trial, 728 women: RR 0.49, 95%CI 0.04 to 5.37).
AUTHORS' CONCLUSIONS: Current best evidence shows that antenatal or postpartum vitamin A supplementation probably has little or no effect on mother-to-child transmission of HIV. According to the GRADE classification, the quality of this evidence is moderate; implying that the true effect of vitamin A supplementation on the risk of mother-to-child transmission of HIV is likely to be close to the findings of this review, but that there is also a possibility that it is substantially different.
对撒哈拉以南非洲地区孕妇的观察性研究表明，血清维生素A水平低与人类免疫缺陷病毒（HIV）母婴传播（MTCT）风险增加有关。维生素A价格低廉，可通过低收入地区现有的卫生服务轻松提供。因此，确定对HIV阳性孕妇或哺乳期妇女常规补充这种维生素对HIV母婴传播风险的影响非常重要，目前全球每天有超过1000例新的HIV感染是由母婴传播导致的。
我们旨在评估产前和/或产后补充维生素A对HIV母婴传播风险以及婴儿和孕产妇死亡率及发病率的影响。
2010年6月，我们检索了Cochrane对照试验中央注册库、PubMed、EMBASE、艾滋病教育全球信息系统和世界卫生组织国际临床试验注册平台；并检查了已识别文章的参考文献列表，以查找在2008年本综述早期版本更新后发表的任何研究。
我们选择了在任何环境中进行的随机对照试验，这些试验比较了已知感染HIV的孕妇或哺乳期妇女补充维生素A与安慰剂的效果。
至少两名作者独立评估试验的合格性和质量并提取数据。我们为每项研究计算了相对风险（RR）或平均差（MD）及其95%置信区间（CI）。我们使用固定效应方法（当研究结果之间无显著异质性时，即P>0.1）或随机效应方法（当存在显著异质性时）进行荟萃分析，并报告所有汇总效应量的希金斯统计量。
五项随机对照试验纳入了7528名感染HIV的妇女（在孕期或产后即刻），符合我们的纳入标准。这些试验于1995年至2005年在马拉维、南非、坦桑尼亚和津巴布韦进行。我们合并了这些试验的结果，发现没有证据表明补充维生素A对HIV母婴传播风险有影响（4项试验，6517名妇女：RR 1.04，95%CI 0.87至1.24；I² = 68%）。然而，产前补充维生素A显著提高了出生体重（3项试验，1809名妇女：MD 89.78，95%CI 84.73至94.83；I² = 33.0%），但没有证据表明对早产有影响（3项试验，2110名妇女：RR 0.88，95%CI 0.65至1.19；I² = 58.1%）、死产（4项试验，2855名妇女：RR 0.99，95%CI 0.68至1.43；I² = 0%）、24个月时的死亡（2项试验，1635名妇女：RR 1.03，95%CI 0.88至1.20；I² = 0%）、产后CD4水平（1项试验，727名妇女：MD -4.00，95%CI -51.06至43.06）和孕产妇死亡（1项试验，728名妇女：RR 0.49，95%CI 0.04至5.37）。
目前的最佳证据表明，产前或产后补充维生素A可能对HIV母婴传播几乎没有影响。根据GRADE分类，该证据的质量为中等；这意味着补充维生素A对HIV母婴传播风险的真实影响可能接近本综述的结果，但也有可能存在很大差异。
