Severity and Associated Factors of COVID-19 Infection among Pregnant and Postpartum Women: A Cross-Sectional Study in Thailand

Abstract

Background: COVID-19 posed a significant global health crisis, affecting millions worldwide, with pregnant women being particularly susceptible to severe illness and mortality. Pregnant individuals infected with COVID-19 were more likely to require intensive care and invasive ventilation compared to non-pregnant individuals. This study aimed to investigate the severity of COVID-19 in pregnant and postpartum women in Thailand and its associated factors.

Methodology: This cross-sectional quantitative study utilized data from the National Pregnant Women and 6-Week Postpartum Women COVID-19 Infection Report System, Health Promotion Bureau, Department of Health, from December 1, 2020, to May 31, 2022. The outcome was the level of severity of COVID-19 infection (no or mild symptoms, and moderate to severe symptoms) among pregnant and postpartum women. The exposures were participants’ characteristics, including age, nationality, COVID-19 vaccination status, and gestational age when infection was assessed. Multivariable logistic regression was used to examine the associations between these characteristics and COVID-19 severity.

Results: The study recruited 12,579 pregnant or postpartum women infected with COVID-19 in Thailand. Most participants experienced no or mild symptoms (87.0%), while the rest had moderate to severe symptoms (13%). Pregnant women with higher age (≥35 years) had the highest likelihood of severe symptoms (adjusted odds ratio: AOR = 1.79, 95%CI: 1.44, 2.24), and non-Thai participants had a significantly higher likelihood of severe symptoms compared to Thais (AOR = 1.17, 95%CI: 1.03, 1.34). Pregnant women who received three doses of the COVID-19 vaccine had the lowest likelihood of severe symptoms (AOR = 0.16, 95%CI: 0.10, 0.27). Participants being infected during the third trimester of pregnancy had a higher likelihood of severe symptoms (AOR = 1.52, 95%CI: 1.22, 1.90).

Conclusion: This study offers significant insights into the severity of COVID-19 among pregnant and postpartum women in Thailand. Despite most participants experiencing no or mild symptoms, it was imperative for the public to implement preventive measures to reduce the risk of severe symptoms and optimize care for this vulnerable group. Moreover, the study identified the influence of maternal age, nationality, COVID-19 vaccination status, and timing of infection on COVID-19 severity. The findings revealed important implications for the implementation of preventive strategies and the optimization of healthcare services for pregnant women during the COVID-19 pandemic.