Do physical activity, psychological health, and food group intake change in early pregnancy before and during COVID-19? A secondary analysis of cohort data from the Korea Nurses' Health Study.

Purpose: This study aimed to compare the physical activity, psychological health, and food group intake of women in their first trimester of pregnancy before and during the coronavirus disease 2019 (COVID-19) pandemic, and to assess these differences according to annual income levels.

Methods: Using pregnancy survey data from the Korea Nurses' Health Study, we analyzed 800 cases (381 pre-COVID-19, 419 COVID-19) for physical activity and psychological health, and 592 cases (296 pre-COVID-19, 296 COVID-19) for food group intake. Data were matched using 1:1 propensity score matching. Physical activity, psychological health, and food group intake were compared between periods and income groups.

Results: During the pandemic, cycling (t=1.48, p=.003), aerobic exercise (t=0.98, p=.046), and light exercise (t=3.91, p<.001) increased while swimming decreased (t=-1.81, p<.001). Lower-income groups showed decreased running (t=-1.50, p=.004), swimming (t=-1.76, p<.001), and aerobic exercise (t=-1.10, p=.042), while higher-income groups showed increased participation in various physical activities. Depression scores decreased significantly in the lower-income group (t=-1.22, p=.022). Regarding food group intake, consumption of soups, stews (t=-1.63, p=.018), vegetables, kimchi, seaweed, and root (t=-1.60, p=.044) decreased during the pandemic. Lower-income groups showed decreased vegetable consumption (t=-1.43, p=.026) and alcohol intake (t=-1.34, p=.039), while higher-income groups showed increased alcohol consumption (t=1.29, p=.010).

Conclusion: The COVID-19 pandemic differently affected health behaviors in early pregnancy based on income levels, highlighting socioeconomic disparities in maintaining healthy behaviors during public health crises. These findings suggest the need for tailored interventions considering income levels when promoting health behaviors among pregnant women during future public health crises.