Trends in the Prevalence of Macrosomia Among Live Births in Greece: A Nationwide Analysis, 1980-2023

Objectives: The present study aimed to estimate macrosomia rates in Greece and investigate their temporal trends during the period 1980-2023. Methods: This nationwide population-based study analyzed official birth registry data obtained from the Hellenic Statistical Authority. The dataset included 4,593,229 live births registered in Greece between 1980 and 2023. For each year, overall macrosomia rates (birth weight ≥4,000 g) and severe macrosomia rates (≥4,500 g) were calculated. Additional analyses were performed separately for grade 1 (4,000-4,499 g), grade 2 (4,500-4,999 g), and grade 3 (≥5,000 g) macrosomia, according to gestational age at delivery (37-39 vs. ≥40 weeks), and among singleton live births. Temporal trends were evaluated using Joinpoint regression analysis, and annual percent change (APC) and average annual percent change (AAPC) values with 95% confidence intervals (95% CI) were calculated. Results: During 1980-2023, the overall macrosomia rate declined by 63%, from 7.66% in 1980 to a historic low of 2.85% in 2023 (AAPC = −2.3, 95% CI: −2.5 to −2.2). The decrease was moderate during 1980-1992 (APC = −1.5, 95% CI: −2.1 to −0.5) and became particularly pronounced between 1992 and 2001 (APC = −4.4, 95% CI: −7.8 to −3.6) and again during 2007-2010 (APC = −10.2, 95% CI: −12.2 to −6.5), following a period of stabilization between 2001 and 2007. After a modest increase during 2010-2020 (APC = 1.4, 95% CI: 0.8 to 2.9), rates declined again during 2020-2023 (APC = −6.9, 95% CI: −12.1 to −3.1). Severe macrosomia (≥ 4,500 g) decreased by 81%, from 10.17 to a record low of 1.95 per 1,000 live births between 1980 and 2023 (AAPC = −3.9, 95% CI: −4.2 to −3.6). Grade 1 macrosomia (4,000-4,499 g), grade 2 macrosomia (4,500-4,999 g), and grade 3 macrosomia (≥ 5,000 g) declined, with corresponding AAPC values of −2.2 (95% CI: −2.3 to −2.0), −3.4 (95% CI: −3.7 to −3.0), and −6.2 (95% CI: −6.8 to −5.7), respectively. Macrosomia rates decreased more markedly among births at 37-39 gestational weeks (AAPC = −2.8, 95% CI: −3.0 to −2.6) than among births at ≥ 40 weeks (AAPC = −1.0, 95% CI: −1.3 to −0.8). Similar declining trends were observed among singleton live births, with the overall macrosomia rate decreasing from 7.80% to 3.02% and severe macrosomia decreasing from 10.36 to 2.06 per 1,000 singleton live births. Conclusions: Since 1980, Greece has achieved substantial reductions in macrosomia rates, which reached historically low levels in 2023. The decline was more pronounced for the more severe categories of macrosomia. Continued surveillance and targeted interventions in high-risk populations may further improve fetal growth outcomes in the country.