Department of Global Health and Population, Harvard University T H Chan School of Public Health, Boston, Massachusetts, USA
Centre for Health Research and Development, Society for Applied Studies, New Delhi, India.
BMJ Glob Health. 2022 Aug;7(8). doi: 10.1136/bmjgh-2021-007537.
Low birth weight (LBW), including preterm birth (PTB) and small for gestational age (SGA), contributes a significant global health burden. We aimed to summarise current evidence on the effect of preconception and periconception interventions on LBW, SGA and PTB.
In this systematic review and meta-analysis, we searched PubMed, Embase, Cochrane Library and WHO Global Index Medicus for randomised controlled trials and quasi-experimental studies published by 28 November 2020, which assessed interventions delivered in preconception and periconception or preconception and pregnancy. Primary outcomes were LBW, SGA and PTB. Studies were categorised by intervention type and delivery during preconception and periconception or during preconception and pregnancy. Estimates were pooled using fixed-effects or random-effects restricted maximum likelihood method meta-analyses. Quality of evidence for primary outcomes was assessed using the Grades of Recommendations, Assessment, Development and Evaluation approach.
We included 58 studies. Twenty-eight studies examined nutrition interventions (primarily micronutrient or food supplementation). Thirty studies (including one reporting a nutrition intervention) provided health interventions (general preconception health, early adverse pregnancy outcome prevention, non-communicable disease and infectious disease prevention and management). One study assessed a social intervention (reproductive planning). Studies varied in terms of specific interventions, including delivery across preconception or pregnancy, resulting in few studies for any single comparison. Overall, the evidence was generally very uncertain regarding the impact of any intervention on LBW, SGA and PTB. Additionally, preconception and periconception nutritional supplementation containing folic acid was associated with reduced risk of birth defects (10 studies, N=3 13 312, risk ratio: 0.37 (95% CI: 0.24 to 0.55), I: 74.33%).
We found a paucity of evidence regarding the impact of preconception and periconception interventions on LBW, SGA and PTB. Further research on a wider range of interventions is required to clearly ascertain their potential effectiveness.
This review was prospectively registered with PROSPERO (CRD42020220915).
低出生体重（LBW），包括早产（PTB）和小于胎龄儿（SGA），对全球健康造成了重大负担。我们旨在总结目前关于孕前和围孕期干预对 LBW、SGA 和 PTB 影响的证据。
在这项系统评价和荟萃分析中，我们检索了 PubMed、Embase、Cochrane 图书馆和世界卫生组织全球医学索引，以获取截至 2020 年 11 月 28 日发表的随机对照试验和准实验研究，评估在孕前和围孕期或孕前和孕期进行的干预措施。主要结局是 LBW、SGA 和 PTB。研究按干预类型和在孕前和围孕期或孕前和孕期进行的分类。使用固定效应或随机效应限制最大似然法荟萃分析汇总估计值。使用推荐、评估、制定和评估方法对主要结局的证据质量进行评估。
我们纳入了 58 项研究。28 项研究检查了营养干预措施（主要是微量营养素或食物补充）。30 项研究（包括一项报告营养干预的研究）提供了健康干预措施（一般孕前健康、早期不良妊娠结局预防、非传染性疾病和传染病预防和管理）。一项研究评估了社会干预措施（生殖计划）。研究在具体干预措施方面存在差异，包括在孕前或孕期进行的干预措施，因此对于任何单一比较，研究数量都很少。总体而言，关于任何干预措施对 LBW、SGA 和 PTB 的影响的证据通常非常不确定。此外，含有叶酸的孕前和围孕期营养补充剂与降低出生缺陷风险相关（10 项研究，N=313312，风险比：0.37（95%CI：0.24 至 0.55），I2=74.33%）。
我们发现关于孕前和围孕期干预对 LBW、SGA 和 PTB 影响的证据很少。需要对更广泛的干预措施进行更多研究，以明确确定其潜在效果。
本综述前瞻性地在 PROSPERO（CRD42020220915）上进行了注册。
