Introduction

: Evidence suggests that vitamin D suppresses the production of pro-inflammatory cytokines and induces the production of anti-inflammatory cytokines during pregnancy.

Objectives

: To assess, through a systematic literature review, the relationship between maternal or cord blood concentrations of 25-hydroxycholecalciferol (25-OH-D) or vitamin D supplementation during pregnancy and the cytokines profile in the umbilical cord.

Methods

: The following databases were searched: PUBMED, CENTRAL, Web of Science, LILACS, and gray literature, up to July 2020. The search strategy included terms related to the exposure (25-OH-D) and the primary outcome (cytokines). Observational studies and randomized clinical trials were included, measuring cytokines in the umbilical cord blood, or in ex vivo bioassays, and blood concentrations of 25-OH-D, either throughout pregnancy or in the umbilical cord blood. Studies with twin pregnancies, with placental or autoimmune diseases, were excluded. The protocol is registered in PROSPERO (number CRD42019136643).

Results

: From 14,605 unique articles identified in the databases, 28 were read in full, and of these, eight met the eligibility criteria, being three randomized clinical trials, and five observational studies. The eight studies showed adequate methodological quality. IL-10 was the most studied cytokine, being reported in seven studies. There were higher concentrations of IL-10 in the umbilical cord of women with 25-OH-D sufficiency in the observational studies. Clinical trials showed mixed results with the use of ex vivo bioassays with several stimulants. Associations with other cytokines were less consistent or absent.

Conclusion

: 25-OH-D status is positively associated with the IL-10 levels of the umbilical cord, in observational studies.

中文翻译：

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妊娠期间母体或脐带血中补充25-羟胆钙化醇或维生素D的浓度与脐带血中细胞因子谱之间的关联：系统文献综述。

介绍

：证据表明，维生素D在怀孕期间会抑制促炎细胞因子的产生并诱导产生抗炎细胞因子。

目标

：通过系统的文献综述，评估孕期孕妇或脐带血中25-羟胆钙化醇（25-OH-D）或维生素D的补充浓度与脐带细胞因子分布之间的关系。

方法

：搜寻了以下数据库：直到2020年7月为止的PUBMED，CENTRAL，Web of Science，LILACS和灰色文献。搜索策略包括与暴露（25-OH-D）和主要结果（细胞因子）相关的术语。包括观察性研究和随机临床试验，在整个怀孕期间或在脐带血中测量脐带血或离体生物测定中的细胞因子，以及25-OH-D的血药浓度。排除双胎妊娠，胎盘或自身免疫性疾病的研究。该协议已在PROSPERO中注册（编号CRD42019136643）。

结果

：从数据库中确定的14,605篇独特文章中，完整阅读了28篇，其中八篇符合资格标准，其中三篇为随机临床试验，另外五篇为观察性研究。八项研究显示了足够的方法学质量。IL-10是研究最多的细胞因子，已有七项研究报道。在观察性研究中，具有25-OH-D功能的女性脐带中IL-10的浓度较高。临床试验显示，使用体外生物测定法与几种兴奋剂的结果不一。与其他细胞因子的关联不太一致或缺乏。

结论

：在观察性研究中，25-OH-D状态与脐带的IL-10水平呈正相关。