Combined Burden of Preterm and Low Birthweight Births in Greece: A Nationwide Time-Trend Analysis

The objective of this study was to assess the combined burden of preterm and low birthweight (LBW) births in Greece from 1980 to 2023, using this measure as a proxy for small vulnerable newborns (SVN), the neonatal population at heightened risk of mortality and of both short- and long-term morbidity.

The analysis included 4,585,090 live births in Greece with complete data from 1980 to 2023. Trends in preterm (< 37 weeks of gestation) and/or LBW (< 2,500 g) births, as well as in the three subcategories (preterm-LBW, preterm-non-LBW, and term-LBW), were assessed using Joinpoint regression analysis (Joinpoint Regression Program, version 5.2.0; National Cancer Institute, Bethesda, MD, USA). Annual percent change (APC) and 95% confidence intervals (CI) were estimated for each category.

The prevalence of SVN declined significantly from 1980 to 1990 (APC = -1.8, 95% CI: -2.7 to -1.1, p < 0.001), reaching an all-time low of 6.98% in 1990. Thereafter, it rose to a historic peak of 15.28% in 2023. The main increase occurred during 1990-2010 (APC = 3.7, 95% CI: 3.5-4.0, p < 0.001), followed by a non-significant upward trend from 2010 to 2023. The proportion of preterm-LBW births increased from 1.69% in 1991 to a historic maximum of 7.14% in 2023. The steepest increases were observed between 1991 and 2006 (APC = 5.5, 95% CI: 3.8-13.5, p = 0.004) and 2006 and 2009 (APC = 14.1, 95% CI: 0.4-16.1, p = 0.038), continuing more slowly thereafter (2009-2023: APC = 1.3, 95% CI: 0.6-2.2, p = 0.026). The proportion of preterm-non-LBW neonates also rose substantially after 1991 (1991-2009: APC = 9.3, 95% CI: 8.6-10.3, p < 0.001), but has stabilized since 2009. By contrast, the proportion of term-LBW neonates declined markedly between 2002 and 2015 (APC = -4.3, 95% CI: -6.8 to -3.5, p = 0.006) and then remained essentially stable during 2015-2023. The overall increase in SVN was accompanied by a large relative rise in preterm LBW, from 23.7% of all SVN in 1991 to 46.7% in 2023.

The prevalence of preterm and/or LBW newborns in Greece has risen markedly since 1990, reaching a historic peak in 2023. Of particular concern, neonates born both preterm and LBW, the most vulnerable subgroup, were the main drivers of this increase and now constitute the largest share of SVN in the country. These findings underscore the urgent need to elevate the prevention of preterm and LBW births to a national public health priority.