Effect of <scp>COVID</scp> ‐19 pandemic on incidence of pregnancy with tuberculosis: A quasi‐experimental analysis

The global pandemic caused by the coronavirus 2019 (COVID-19) resulted in an unprecedented healthcare crisis and case-fatality (778 691 725 cases and 7 102 530 deaths as of October 13, 2025).1 The chance of transmission of this respiratory virus is higher in a more populous household,2 raising a possible hypothesis that the COVID-19 lockdown may have impacted on other respiratory virus transmissions, such as tuberculosis. As pregnancy with tuberculosis is associated with significant maternal morbidity and mortality,3 and given scarcity in data, we examined the possible cause-and-effect of the COVID-19 pandemic and the incidence of pregnancy with tuberculosis. We queried the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project National Inpatient Sample.4 We selected this database because nearly 4500 hospitals participate across 48 states and the District of Columbia in the program and weighted data represents more than 90% of the US population, enabling us to assess the grand-overview of pregnancy with tuberculosis at national scale.5 The study population included hospital delivery admissions, either vaginal or cesarean, from 2016 to 2022. Selection of vaginal and cesarean deliveries followed prior investigations.6 The WHO's International Classification of Disease (10th revision clinical modification code) was used for the surrogacy of active tuberculosis (A15-A19 and O98.0). The code of U07.1 was used for the COVID-19 diagnosis per the Centers for Disease Control and Prevention definition.7 Incidence rate of pregnancy with tuberculosis was aggregated and summarized per year-quarter, and generalized linear model was fitted to assess the temporal trend of pregnancy with tuberculosis. To assess the possible cause-and-effect of the COVID-19 pandemic on the incidence trend of pregnancy with tuberculosis, a quasi-experimental analysis with interrupted-time series was performed in this study. Specifically, the study period was dissected into the pre-pandemic period and the pandemic period, using the cutpoint of the second year-quarter of 2020. Temporal trend was then estimated in each study period, and the trajectory of pre-pandemic period was used to estimate the expected incidence rate of pregnancy with tuberculosis in the pandemic period. The difference in the expected-to-observed incidence rate of pregnancy with tuberculosis was interpreted as the possible effect of COVID-19 pandemic in this study. All statistical analyses were based on two-tailed hypothesis, and a P value of less than 0.05 was considered statistically significant. The University of Southern California Institutional Review Board deemed this study exempt due to the use of publicly available, deidentified secondary data (registration no. HS-16-00481; informed consent, not required). A total of 24 973 288 hospital deliveries were evaluated for statistical analysis. During the 7-year study period, 2380 hospital deliveries had a diagnosis of tuberculosis, corresponding to 9.5 per 100 000 deliveries or 1 in 10 493 deliveries. Prior to the COVID-19 pandemic, the incidence rate of pregnancy with tuberculosis decreased by 58.6% from 12.8 per 100 000 hospital deliveries in the first year-quarter of 2016 to 5.3 per 100 000 hospital deliveries in the second year-quarter of 2020 (year-quarter decreasing rate 0.3 per 100 000, 95% confidence interval 0.2 to 0.4, P < 0.001; blueline in Figure 1). However, during the pandemic period, the incidence rate of pregnancy with tuberculosis increased by 75.6% from 7.8 per 100 000 hospital deliveries in the third year-quarter of 2020 to 13.7 per 100 000 hospital deliveries in the last year-quarter of 2022 (year-quarter increasing rate 0.6 per 100 000, 95% confidence interval 0.4 to 0.8, P < 0.001; red line in Figure 1). If the trajectory of the COVID-19 pre-pandemic temporal trend continued, the expected incidence rate of pregnancy with tuberculosis would have been 3.1 per 100 000 hospital deliveries by the last year-quarter of 2022 (light green color; Figure 1). The expected-to-observed difference in the incidence rate of pregnancy with tuberculosis at the last year-quarter of 2022 was thus estimated as gradual increase by 10.6 per 100 000 hospital deliveries. The results of this hypothesis-generating exploratory analysis suggest that the COVID-19 pandemic may have possibly caused, or at least contributed, to the increase in tuberculosis cases in pregnancy. This is in line with the temporal trend of global tuberculosis burden. According to The WHO's 2022 global tuberculosis report, global tuberculosis epidemic worsened during the COVID-19 pandemic that reversed the pre-pandemic downtrend.8 As their analysis did not specifically examine the pregnant population, the results in this study provide important information in the perinatal care. While the exact reason for the increase in pregnancy with tuberculosis was not assessable in this study, it is most likely multifactorial with plausible hypotheses including direct (e.g., lockdown effect in built environment) and indirect (e.g., limited access to healthcare) etiologies. Further investigation is warranted to evaluate these hypotheses. Unmeasured confounding in this study included the lack of information on the details of tuberculosis (severity, diagnosis timing, and treatment), comorbidities pertinent to tuberculosis (e.g., human immunodeficiency disease infection), and neighborhood socioeconomic status. Despite these limitations, the results of this nationwide assessment call for attention and evaluation of pregnancy with tuberculosis. Conceptualization: A.Y. Data curation, formal analysis, funding acquisition, methodology, project administration, software, validation and visualization: K.M. Investigation: all authors. Resources: S.M. and J.G.O. Supervision: K.M., S.M. and J.G.O. Writing – original draft: A.Y. and K.M. Writing – review and editing: All authors. Ensign Endowment for Gynecologic Cancer Research (K.M.). The funder had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. None. The data on which this study is based are publicly available upon request at Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality. https://hcup-us.ahrq.gov/nisoverview.jsp.