DHA in Pregnancy and Immune Function in Mexican Infants

描述（由申请人提供）：我们正在墨西哥Cuernavaca的孕妇中进行一项随机、双盲对照试验，研究每天补充200毫克二十二碳六烯酸（DHA）直到分娩对a)出生结局b)母体血液和母乳DMA水平c)产后生长发育和d)婴儿DHA状态的影响。这是埃默里大学国际卫生系和墨西哥国家卫生研究所的一项合作努力。本补充研究的重点是评估DHA补充对婴儿免疫功能的影响。我们将分析目前作为父母研究方案的一部分收集的婴儿血浆和母乳样本。DHA和其他n-3多不饱和脂肪酸已被证明可以调节人体的免疫功能；然而，很少有研究涉及DHA的独立作用。补充研究的中心假设是，孕妇在怀孕期间补充DHA会调节婴儿的免疫功能，该假设将通过测量婴儿免疫功能指标进行检验，包括在出生时（脐带血）和3个月时测量血浆中的总免疫球蛋白（Ig）浓度和IgG亚类浓度。在常规接种1剂白喉疫苗后，将在3个月的婴儿中测量抗原特异性抗体反应。我们将在产后1个月和3个月测量母乳中的IgA浓度。父母研究确定的样本量为每组116对母子。免疫评估将由亚特兰大疾病控制中心免费完成。在确保随机化的有效性后，数据分析将包括组间比较（意向治疗）。如果需要控制潜在的混杂因素，将进行调整比较（使用协方差分析）。据我们所知，目前还没有研究评估孕妇在孕期补充DHA对婴儿免疫功能的影响。

DESCRIPTION (provided by applicant): We are conducting a randomized, double-blinded controlled trial among pregnant women in Cuernavaca, Mexico, to study the effect of daily supplementation with 200 mg docosahexaenoic acid (DHA) until delivery on a) birth outcomes b) maternal blood and breast milk DMA levels c) postnatal growth and development and d) infant DHA status. This is a collaborative effort among the Department of International Health, Emory University, and the Institute Nacional de Salud Publica in Mexico. The focus of this supplemental study is to evaluate the effect of DHA supplementation on infant immune function. We will analyze infant plasma and maternal breast milk samples currently being collected as part of the parent study protocol. DHA and other n-3 polyunsaturated fatty acids have been shown to modulate immune function in humans; however, few studies have addressed the independent effect of DHA. The central hypothesis of the supplemental study, that maternal DHA supplementation in pregnancy will modulate infant immune function, will be tested by measuring indicators of infant immune function including total immunoglobulin (Ig) concentrations and IgG sub-class concentrations in plasma, to be measured at birth (cord blood) and at 3 months. Antigen-specific antibody response after routine vaccination with 1 dose of diphtheria vaccine will be measured in infants at 3 months. We will measure breast milk IgA concentrations at 1 and 3 months post-partum. The sample size fixed by the parent study will be 116 mother-child pairs per group. The immunological assessments will be done at no cost to the study by the Centers for Disease Control, Atlanta. Data analysis will include group comparisons (intent-to-treat) after ensuring effectiveness of randomization. Adjusted comparisons (using co-variance analysis) will be made if control for potential confounders is required. To our knowledge, there are no studies that have evaluated the impact of maternal DHA supplementation in pregnancy on infant immune function.