Preterm birth is the leading cause of neonatal mortality and is associated with long-term physical, neurodevelopmental, and socioeconomic effects. This study updated national preterm birth rates and trends, plus novel estimates by gestational age subgroups, to inform progress towards global health goals and targets, and aimed to update country, regional, and global estimates of preterm birth for 2020 in addition to trends between 2010 and 2020. We systematically searched population-based, nationally representative data on preterm birth from Jan 1, 2010, to Dec 31, 2020 and study data (26 March–14 April, 2021) for countries and areas with no national-level data. The analysis included 679 data points (86% nationally representative administrative data [582 of 679 data points]) from 103 countries and areas (62% of countries and areas having nationally representative administrative data [64 of 103 data points]). A Bayesian hierarchical regression was used for estimating country-level preterm rates, which incoporated country-specific intercepts, low birthweight as a covariate, non-linear time trends, and bias adjustments based on a data quality categorisation, and other indicators such as method of gestational age estimation. An estimated 13·4 million (95% credible interval [CrI] 12·3–15·2 million) newborn babies were born preterm (<37 weeks) in 2020 (9·9% of all births [95% CrI 9·1–11·2]) compared with 13·8 million (12·7–15·5 million) in 2010 (9·8% of all births [9·0–11·0]) worldwide. The global annual rate of reduction was estimated at –0·14% from 2010 to 2020. In total, 55·6% of total livebirths are in southern Asia (26·8% [36 099 000 of 134 767 000]) and sub-Saharan Africa (28·7% [38 819 300 of 134 767 000]), yet these two regions accounted for approximately 65% (8 692 000 of 13 376 200) of all preterm births globally in 2020. Of the 33 countries and areas in the highest data quality category, none were in southern Asia or sub-Saharan Africa compared with 94% (30 of 32 countries) in high-income countries and areas. Worldwide from 2010 to 2020, approximately 15% of all preterm births occurred at less than 32 weeks of gestation, requiring more neonatal care (<28 weeks: 4·2%, 95% CI 3·1–5·0, 567 800 [410 200–663 200 newborn babies]); 28–32 weeks: 10·4% [9·5–10·6], 1 392 500 [1 274 800–1 422 600 newborn babies]). There has been no measurable change in preterm birth rates over the last decade at global level. Despite increasing facility birth rates and substantial focus on routine health data systems, there remain many missed opportunities to improve preterm birth data. Gaps in national routine data for preterm birth are most marked in regions of southern Asia and sub-Saharan Africa, which also have the highest estimated burden of preterm births. Countries need to prioritise programmatic investments to prevent preterm birth and to ensure evidence-based quality care when preterm birth occurs. Investments in improving data quality are crucial so that preterm birth data can be improved and used for action and accountability processes. The Children's Investment Fund Foundation and the UNDP, United Nations Population Fund-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction.

中文翻译：

---

2020 年国家、地区和全球早产估计以及 2010 年趋势：系统分析

早产是新生儿死亡的主要原因，并与长期的身体、神经发育和社会经济影响有关。这项研究更新了国家早产率和趋势，以及按胎龄亚组进行的新估计，以通报全球健康目标和指标的进展情况，并旨在更新国家、区域和全球 2020 年早产的估计以及 2010 年之间的趋势我们系统地检索了2010年1月1日至2020年12月31日基于人口的、具有全国代表性的早产数据，以及没有国家级数据的国家和地区的研究数据（2021年3月26日至4月14日）。该分析包括来自 103 个国家和地区的 679 个数据点（86% 具有国家代表性的行政数据[679 个数据点中的 582 个]）（62% 的国家和地区拥有具有国家代表性的行政数据[103 个数据点中的 64 个]）。贝叶斯分层回归用于估计国家级早产率，其中纳入了特定国家的截距、低出生体重作为协变量、非线性时间趋势以及基于数据质量分类的偏差调整和其他指标，例如胎龄估计。据估计，2020 年有 13·400 万（95% 可信区间 [CrI] 12·3–15·200 万）新生儿早产（<37 周）（占所有新生儿的 9·9% [95% CrI 9·1] –11·2]），而 2010 年全球出生人数为 13·800 万（12·7–15·500 万）（占所有出生人口的 9·8% [9·0–11·0]）。2010 年至 2020 年，全球年减少率估计为 –0·14%。总共，活产总数的 55·6% 发生在南亚（26·8% [134 767 000 中的 36 099 000]）和亚-撒哈拉非洲地区（28·7% [134 767 000 例中的​​ 38 819 300 例]），但这两个地区约占 2020 年全球早产总数的 65%（13 376 200 例中的​​ 8 692 000 例）。在 33 个国家和地区中，在最高数据质量类别的地区中，没有一个位于南亚或撒哈拉以南非洲，而 94%（32 个国家中的 30 个）位于高收入国家和地区。2010 年至 2020 年，全球范围内约 15% 的早产发生在妊娠 32 周以下，需要更多的新生儿护理（<28 周：4·2%，95% CI 3·1–5·0, 567 800 [ 410 200–663 200 名新生儿])；28–32 周：10·4% [9·5–10·6]，1 392 500 [1 274 800–1 422 600 新生儿]）。过去十年，全球早产率没有发生明显变化。尽管设施出生率不断提高，并且大力关注常规健康数据系统，但仍然错失了许多改善早产数据的机会。国家早产常规数据的差距在南亚和撒哈拉以南非洲地区最为明显，这些地区的早产估计负担也最高。各国需要优先进行规划投资，以预防早产，并确保早产发生时基于证据的优质护理。对提高数据质量的投资至关重要，这样才能改善早产数据并将其用于行动和问责流程。儿童投资基金基金会和开发计划署、联合国人口基金-儿童基金会-世界卫生组织-世界银行人类生殖研究、发展和研究培训特别规划。