Declining birth outcomes during the COVID-19 pandemic: a nationwide study in South Korea

Objective: This study aimed to investigate the impact of the coronavirus disease (COVID-19) pandemic on birth outcomes in South Korea, particularly in the context of exceptionally low birth rates. Methods: Using nationwide birth certificate data up to 2022, an interrupted time-series analysis, linear probability model, and subgroup analyses were conducted to assess the influence of the pandemic on perinatal outcomes. Results: The analysis revealed a transient increase in preterm births of 0.15% (95% CI: 0.00%, 0.03%) and a sustained rise of 0.01% (95% CI: 0.00%, 0.02%) following the onset of the pandemic. In contrast, low birth weight initially showed a short-term decline of -0.11% (95% CI: -0.24%, -0.02%), followed by an intermediate-term increase of 0.02% (95% CI: 0.01%, 0.03%). Subgroup analyses indicated that these adverse birth outcomes were more pronounced among women under 35 years old, those with higher education levels, and those who were employed. Conclusions: These findings suggest that the COVID-19 pandemic may have exacerbated pre-existing adverse trends in birth outcomes in South Korea. The results highlight the need to strengthen not only healthcare and social support for pregnant women, but also protective policies for those in the workforce particularly during large-scale public health crises.