Importance Multiple sclerosis (MS) relapses may be increased in the postpartum period, and whether breastfeeding is associated with reduction in the risk of postpartum relapses remains controversial. Objective To perform a systematic review and meta-analysis to evaluate whether breastfeeding is associated with reduction in postpartum MS relapses compared with not breastfeeding. Data Sources PubMed and Embase were searched for studies assessing the association between breastfeeding and MS disease activity published between January 1, 1980, and July 11, 2018, as well as reference lists of selected articles. Study Selection All study designs assessing the association between breastfeeding and postpartum relapses in MS relative to a comparator group were included. Data Extraction and Synthesis Study eligibility assessment and extraction of study characteristics, methods, and outcomes, were performed independently by 2 reviewers following PRISMA guidelines. Risk of bias was evaluated by 2 independent reviewers with the ROBINS-I tool for nonrandomized, interventional studies. Findings from studies with data available for the number of women with postpartum relapses in the breastfeeding and nonbreastfeeding groups were combined with a random-effects model. Main Outcomes and Measures Postpartum MS relapse. Results The search identified 462 unique citations, and 24 (2974 women) satisfied eligibility criteria and were included, of which 16 were included in the quantitative meta-analysis. The pooled summary odds ratio for the association of breastfeeding with postpartum relapses was 0.63 (95% CI, 0.45-0.88; P = .006) compared with a reference of nonbreastfeeding. Pooled adjusted hazard ratio across 4 studies that reported this finding was 0.57 (95% CI, 0.38-0.85; P = .006). There was moderate heterogeneity (I2 = 48%), which was explained by variable prepregnancy relapse rate, postpartum follow-up duration, and the publication year. A stronger association was seen in studies of exclusive rather than nonexclusive breastfeeding, although both demonstrated an association. Studies were rated at moderate and serious risk of bias, with concern for residual confounding, although sensitivity analysis including only moderate quality studies was consistent with a protective outcome of breastfeeding. Conclusions and Relevance These findings suggest that breastfeeding is protective against postpartum relapses in MS, although high-quality prospective studies to date are limited and well-designed observational studies that aim to emulate a randomized trial would be of benefit.

中文翻译：

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母乳喂养与产后多发性硬化症复发之间的关联：系统评价和荟萃分析。

重要性产后多发性硬化症（MS）复发可能增加，并且母乳喂养是否与降低产后复发风险相关仍存在争议。目的进行系统的回顾和荟萃分析，以评估母乳喂养与未母乳喂养相比是否与减少产后MS复发有关。搜索数据来源PubMed和Embase进行的研究评估了母乳喂养与1980年1月1日至2018年7月11日发表的MS疾病活动之间的关联，以及选定文章的参考清单。研究选择包括所有评估母乳喂养与相对于比较组的MS产后复发之间的相关性的研究设计。数据提取和综合研究资格的评估和研究特征，方法和结果的提取由2位审阅者按照PRISMA指南独立进行。由2名独立审阅者使用ROBINS-I工具评估偏倚风险，以进行非随机干预研究。研究的结果与母乳喂养和非母乳喂养组中产后复发妇女人数的可用数据结合了随机效应模型。主要结果和措施产后MS复发。结果搜索确定了462个独特的引文，其中24个（2974名女性）符合入选标准，被纳入其中，其中16个被纳入定量荟萃分析中。母乳喂养与产后复发相关的汇总汇总优势比为0.63（95％CI，0.45-0.88; P = .006）与非母乳喂养参考相比。在报告有此发现的4项研究中，合并调整后的危险比为0.57（95％CI，0.38-0.85； P = .006）。有中等程度的异质性（I2 = 48％），这可以通过可变的妊娠复发率，产后随访时间和出版年份来解释。在纯母乳喂养而非非母乳喂养的研究中发现了更强的关联，尽管两者均显示出关联。尽管敏感性分析（仅包括中等质量的研究）与母乳喂养的保护性结果一致，但对研究的评级为中等偏重和严重偏倚风险，并关注残留混杂因素。结论和相关性这些发现表明，母乳喂养可以预防MS的产后复发，