Born too soon: global epidemiology of preterm birth and drivers for change

Abstract

Progress: There has been no measurable change in global preterm birth rates in the past decade, in any region. A handful of countries have reduced their preterm birth rates, but only marginally (0.5 percentage points annually), and there has been little progress in availability of preterm birth data globally. An estimated 13.4 million (95% credible interval (CrI): [12.3, 15.2 million]) newborns were preterm or "born too soon" in 2020, 9.9% (95% CrI: [9.1, 11.2%]) of births worldwide. Preterm birth complications remained the top cause of under-5 child mortality globally in 2022, accounting for about 1 million neonatal deaths, similar to figures a decade ago. More encouragingly, some countries have improved data systems to better capture preterm birth information and advancements have been made in gestational age measurement, highlighting targeted efforts towards improving data for action. This paper is part of a series based on the report "Born too soon: decade of action on preterm birth".

Programmatic priorities: Preventing preterm birth is a critical priority and could be accelerated by focusing on context-specific risk factors, and addressing spontaneous and provider-initiated preterm births, including non-medically indicated caesarean sections. Effective care can prevent 900 000 deaths from complications of preterm birth, particularly among those born before 32 weeks' gestation. Stillbirths should be included in data, policies and programmes relating to preterm birth. Most stillbirths occur preterm (an estimated 74.3%) and have a profound, long-lasting impact on families. Addressing stillbirths is essential for reducing the overall burden of preterm birth and minimising loss of human capital.

Pivots: It is important that the data are available and of high quality, plus are used to drive action. We focus on three pivots to improve in the next decade: (1) counting every baby everywhere, including those stillborn, and accurately recording gestational age and birthweight; (2) strengthening national data systems to improve the availability of individual-level data for action, including quality improvement in maternity wards and small and sick newborn care units, plus follow-up for long-term health outcomes including disabilities; and (3) using data to strengthen shared accountability at all levels, from the community to global levels.

Keywords: Accountability; Data; Neonatal; Preterm birth; Prevention; Risk factors; Stillbirths.

Fig. 1

Data and estimates for preterm birth: timeline of progress over the past decade and vision for the next decade SDG – sustainable development goals; ICD – International Classification of Disease [9]. *SDG 3.2 and Every Newborn Action Plan (ENAP) targets to end preventable deaths of newborns and children under 5, with all countries reducing neonatal mortality rate to at least 12 per 1000 livebirths. There is also a linked ENAP stillbirth target reducing stillbirth rate [10, 11]. Preventing preterm birth and improving care for those born too soon is integral to achieving SDG 3.2 and ENAP mortality targets

Fig. 2

Trends in annual number of preterm births by sustainable development goal regions, 2010–2020 Data from WHO/UNICEF preterm birth estimates, Ohuma, Moller, Bradley et al. [12]. Source: Lawn et al. [13]

Fig. 3

Estimated national preterm birth rates and numbers in 2020 * Only national rates shown. CrI – Credible interval. Source: Adapted from WHO/UNICEF preterm estimates. Ohuma, Moller, Bradley et al. [12]

Fig. 4

Preterm birth by gestational age and region in 2020 Data Source: Adapted from WHO/UNICEF preterm estimates. Ohuma, Moller, Bradley et al. [12]

Fig. 5

Regional variation in the proportion of preterm births resulting in neonatal deaths in 2020 In each pie chart darker shading in indicates proportion of preterm births with neonatal death (first 28 days), by region. Data sources: Preterm birth numbers by country from Ohuma et al. [12]. Mortality estimates generated by applying country specific 2019 preterm cause-specific neonatal death proportions from Perrin et al. [22] to 2020 country-specific live birth estimates from World Population Prospects (https://population.un.org/wpp/) [23]

Fig. 6

13.4 million preterm births in 2020: human capital implications and health system requirements. Around three quarters of stillbirths are preterm in high- and upper-middle-income settings [13] ^e In addition to newborn care, health systems need to be designed to provide care after a stillbirth or death in this high-risk population and to cater throughout the care continuum for the increased health-care needs associated with preterm birth [19]. Adapted from Lawn et al. [13]

Fig. 7

Four types of vulnerable newborns amongst stillbirths Source: Lawn et al. [13]

Fig. 8

Missed opportunities to improve capture of national administrative data on preterm birth, by SDG region, 2010–2020 ¹Excluding Australia and New Zealand. Figure represents gaps for 194 WHO Member States and the occupied Palestinian territory, including east Jerusalem. ≥80% coverage of four antenatal visits was used as a proxy for early antenatal attendance and gestational assessment, noting that this is an imperfect proxy. Adapted from Lawn et al. [13]