Vitamin C supplementation in pregnancy.
Vitamin C supplementation in pregnancy.
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DOI：
10.1002/14651858.cd004072.pub3
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发表时间：
2015-09
期刊：
影响因子：
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通讯作者：
A. Rumbold;E. Ota;Chie Nagata;Sadequa Shahrook;C. Crowther
中科院分区：
文献类型：
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作者：
A. Rumbold;E. Ota;Chie Nagata;Sadequa Shahrook;C. Crowther
背景补充维生素C可能有助于降低妊娠并发症的风险，如先兆子痫、宫内生长受限和母体贫血。有必要评估孕期补充维生素C的有效性和安全性。目的评价维生素C单独或联合补充对妊娠结局、不良事件、副作用及卫生资源利用的影响。方法检索Cochrane妊娠和分娩组的临床试验登记表(2015年3月31日)和检索到的研究的参考文献列表。选择标准所有评估孕妇维生素C补充剂的随机或准随机对照试验。使用含有维生素C的复合维生素补充剂或主要补充剂为铁的干预措施被排除在外。数据收集和分析两位综述作者独立评估了试验的纳入和偏见风险，提取了数据并检查了它们的准确性。主要结果纳入29个试验，涉及24,300名妇女。总体而言，11项试验被判定为低偏见风险，8项被判定为高偏见风险，10项试验被判断为不清楚。单独补充维生素C或与其他补充剂联合使用的妇女与安慰剂或不补充其他补充剂的妇女相比，在死产风险(风险比(RR)1.15，95%可信区间(CI)0.89至1.49；20,038名参与者；11项研究；I？=0%；中等质量证据)、新生儿死亡(RR 0.79，95%CI 0.58至1.08；19,575名参与者；11项研究；I²=0%)、围产期死亡(RR平均1.07，95%CI 0.77至1.49；17,105名参与者；7项研究；出生体重(平均差异(MD)26.88 g，95%CI-18.81至72.58；17,326名参与者；13项研究；I²=69%)；宫内发育受限(RR 0.98，95%CI 0.91至1.06；20,361名参与者；12项研究；I²=15%；高质量证据)，早产(平均RR 0.99，95%CI 0.90至1.10；22,250名参与者；16项研究；I²=49%；早产胎膜早破(平均RR 0.98，95%可信区间0.70~1.36；16,825名参与者；10项研究；指数=70%；低质量证据)；足月胎膜早破(平均RR 1.26，95%可信区间0.62~2.56；2674名参与者；3项研究；指数指数=87%)；临床先兆子痫(平均RR 0.92，95%可信区间0.80~1.05；21,956名参与者；16项研究；指数=41%；与安慰剂或不补充其他补充剂相比，补充维生素C或与其他补充剂联合使用的妇女发生胎盘早剥的风险降低(RR 0.64，95%CI 0.44至0.92；15,755名参与者；8项研究；I？=0%；高质量证据)，出生时胎龄略有增加(MD 0.31，95%CI 0.01至0.61；14,062名参与者；9项研究；I²=65%)，但她们也更有可能自我报告腹痛(RR 1.66，95%CI 1.16至2.37；1877名参与者；一项研究)。在基于补充剂类型的亚组分析中，单独补充维生素C与早产胎膜早破(平均RR 0.66，95%可信区间0.48至0.91；1282名参与者；5项研究；指数=0%)和足月胎膜早破(平均RR 0.55，95%可信区间0.32至0.94；170名参与者；一项研究)的风险降低相关。相反，当补充维生素C和维生素E时，足月胎膜早破的风险增加(平均RR为1.73，95%可信区间为1.34至2.23；3060名参与者；两项研究；指数=0%)。在检查补充剂类型的亚组分析中，维生素C对其他结果的影响没有差异。在其他妇女亚组中，根据潜在的妊娠并发症风险、开始补充维生素C的时间或试验进入前的饮食摄入，没有不同的模式。胎儿宫内发育受限、早产和胎盘早剥的证据质量等级较高，死产和临床先兆子痫的证据质量中等，早产胎膜早破的证据质量较低。作者的结论：这些数据不支持单独或与其他补充剂联合使用常规维生素C来预防胎儿或新生儿死亡、胎儿发育不良、早产或先兆子痫。需要进一步的研究来阐明维生素C在预防胎盘早剥和产前胎膜破裂中的可能作用。没有令人信服的证据表明，单独补充维生素C或与其他补充剂联合使用会导致其他重要的益处或危害。
BACKGROUND Vitamin C supplementation may help reduce the risk of pregnancy complications such as pre-eclampsia, intrauterine growth restriction and maternal anaemia. There is a need to evaluate the efficacy and safety of vitamin C supplementation in pregnancy. OBJECTIVES To evaluate the effects of vitamin C supplementation, alone or in combination with other separate supplements on pregnancy outcomes, adverse events, side effects and use of health resources. SEARCH METHODS We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 March 2015) and reference lists of retrieved studies. SELECTION CRITERIA All randomised or quasi-randomised controlled trials evaluating vitamin C supplementation in pregnant women. Interventions using a multivitamin supplement containing vitamin C or where the primary supplement was iron were excluded. DATA COLLECTION AND ANALYSIS Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. MAIN RESULTS Twenty-nine trials involving 24,300 women are included in this review. Overall, 11 trials were judged to be of low risk of bias, eight were high risk of bias and for 10 trials it was unclear. No clear differences were seen between women supplemented with vitamin C alone or in combination with other supplements compared with placebo or no control for the risk of stillbirth (risk ratio (RR) 1.15, 95% confidence intervals (CI) 0.89 to 1.49; 20,038 participants; 11 studies; I² = 0%; moderate quality evidence), neonatal death (RR 0.79, 95% CI 0.58 to 1.08; 19,575 participants; 11 studies; I² = 0%), perinatal death (average RR 1.07, 95% CI 0.77 to 1.49; 17,105 participants; seven studies; I² = 35%), birthweight (mean difference (MD) 26.88 g, 95% CI -18.81 to 72.58; 17,326 participants; 13 studies; I² = 69%), intrauterine growth restriction (RR 0.98, 95% CI 0.91 to 1.06; 20,361 participants; 12 studies; I² = 15%; high quality evidence), preterm birth (average RR 0.99, 95% CI 0.90 to 1.10; 22,250 participants; 16 studies; I² = 49%; high quality evidence), preterm PROM (prelabour rupture of membranes) (average RR 0.98, 95% CI 0.70 to 1.36; 16,825 participants; 10 studies; I² = 70%; low quality evidence), term PROM (average RR 1.26, 95% CI 0.62 to 2.56; 2674 participants; three studies; I² = 87%), and clinical pre-eclampsia (average RR 0.92, 95% CI 0.80 to 1.05; 21,956 participants; 16 studies; I² = 41%; high quality evidence).Women supplemented with vitamin C alone or in combination with other supplements compared with placebo or no control were at decreased risk of having a placental abruption (RR 0.64, 95% CI 0.44 to 0.92; 15,755 participants; eight studies; I² = 0%; high quality evidence) and had a small increase in gestational age at birth (MD 0.31, 95% CI 0.01 to 0.61; 14,062 participants; nine studies; I² = 65%), however they were also more likely to self-report abdominal pain (RR 1.66, 95% CI 1.16 to 2.37; 1877 participants; one study). In the subgroup analyses based on the type of supplement, vitamin C supplementation alone was associated with a reduced risk of preterm PROM (average RR 0.66, 95% CI 0.48 to 0.91; 1282 participants; five studies; I² = 0%) and term PROM (average RR 0.55, 95% CI 0.32 to 0.94; 170 participants; one study). Conversely, the risk of term PROM was increased when supplementation included vitamin C and vitamin E (average RR 1.73, 95% CI 1.34 to 2.23; 3060 participants; two studies; I² = 0%). There were no differences in the effects of vitamin C on other outcomes in the subgroup analyses examining the type of supplement. There were no differing patterns in other subgroups of women based on underlying risk of pregnancy complications, timing of commencement of supplementation or dietary intake of vitamin C prior to trial entry. The GRADE quality of the evidence was high for intrauterine growth restriction, preterm birth, and placental abruption, moderate for stillbirth and clinical pre-eclampsia, low for preterm PROM. AUTHORS' CONCLUSIONS The data do not support routine vitamin C supplementation alone or in combination with other supplements for the prevention of fetal or neonatal death, poor fetal growth, preterm birth or pre-eclampsia. Further research is required to elucidate the possible role of vitamin C in the prevention of placental abruption and prelabour rupture of membranes. There was no convincing evidence that vitamin C supplementation alone or in combination with other supplements results in other important benefits or harms.