CIET/PRAM, Department of Family Medicine, McGill University, 5858 Chemin de la Côte-des-Neiges 3rd Floor, Suite 300, Montreal, Quebec, H3S 1Z1, Canada.
Facultad de Medicina, Universidad de La Sabana, Campus Universitario puente del común, Chía, Colombia, CP, 250001.
BMC Pregnancy Childbirth. 2020 Mar 12;20(1):156. doi: 10.1186/s12884-020-2852-z.
There is ample evidence of associations between short birth interval and adverse maternal and child health outcomes, including infant and maternal mortality. Short birth interval is more common among women in low- and middle-income countries. Identifying actionable aspects of short birth interval is necessary to address the problem. To our knowledge, this is the first systematic review to systematize evidence on risk factors for short birth interval in low- and middle-income countries.
A systematic mixed studies review searched PubMed, Embase, LILACS, and Popline databases for empirical studies on the topic. We included documents in English, Spanish, French, Italian, and Portuguese, without date restriction. Two independent reviewers screened the articles and extracted the data. We used the Mixed Methods Appraisal Tool to conduct a quality appraisal of the included studies. To accommodate variable definition of factors and outcomes, we present only a narrative synthesis of the findings.
Forty-three of an initial 2802 documents met inclusion criteria, 30 of them observational studies and 14 published after 2010. Twenty-one studies came from Africa, 18 from Asia, and four from Latin America. Thirty-two reported quantitative studies (16 studies reported odds ratio or relative risk, 16 studies reported hazard ratio), 10 qualitative studies, and one a mixed-methods study. Studies most commonly explored education and age of the mother, previous pregnancy outcome, breastfeeding, contraception, socioeconomic level, parity, and sex of the preceding child. For most factors, studies reported both positive and negative associations with short birth interval. Shorter breastfeeding and female sex of the previous child were the only factors consistently associated with short birth interval. The quantitative and qualitative studies reported largely non-overlapping results.
Promotion of breastfeeding could help to reduce short birth interval and has many other benefits. Addressing the preference for a male child is complex and a longer-term challenge. Future quantitative research could examine associations between birth interval and factors reported in qualitative studies, use longitudinal and experimental designs, ensure consistency in outcome and exposure definitions, and include Latin American countries.
Prospectively registered on PROSPERO (International Prospective Register for Systematic Reviews) under registration number CRD42018117654.
大量证据表明，短生育间隔与母婴健康不良结局有关，包括婴儿和产妇死亡。在中低收入国家，生育间隔较短的情况更为常见。确定短生育间隔的可操作方面对于解决这一问题是必要的。据我们所知，这是首次对中低收入国家短生育间隔风险因素进行系统综述的研究。
一项系统的混合研究综述在 PubMed、Embase、LILACS 和 Popline 数据库中搜索了关于该主题的实证研究。我们纳入了英文、西班牙文、法文、意大利文和葡萄牙文的文献，没有时间限制。两名独立评审员筛选了文章并提取了数据。我们使用混合方法评估工具对纳入的研究进行了质量评估。为了适应因素和结果的可变定义，我们仅对研究结果进行了叙述性综合。
在最初的 2802 篇文献中，有 43 篇符合纳入标准，其中 30 篇为观察性研究，14 篇发表于 2010 年后。21 篇研究来自非洲，18 篇来自亚洲，4 篇来自拉丁美洲。32 篇报告了定量研究（16 篇研究报告了比值比或相对风险，16 篇研究报告了风险比），10 篇定性研究，1 篇混合方法研究。研究最常探讨母亲的教育和年龄、上次妊娠结局、母乳喂养、避孕、社会经济水平、产次和前一个孩子的性别。对于大多数因素，研究报告了与短生育间隔的正相关和负相关。较短的母乳喂养时间和前一个孩子的性别是唯一与短生育间隔一致相关的因素。定量和定性研究报告的结果基本上没有重叠。
促进母乳喂养有助于减少短生育间隔，而且还有许多其他好处。解决对男孩的偏好是一个复杂且长期的挑战。未来的定量研究可以检验生育间隔与定性研究中报告的因素之间的关联，使用纵向和实验设计，确保结果和暴露定义的一致性，并纳入拉丁美洲国家。
在 PROSPERO（系统评价国际前瞻性注册库）上进行了前瞻性注册，注册号为 CRD42018117654。
