Bacterial superinfection in pregnant women with severe COVID-19: Prevalence, resistance patterns and outcomes

Pregnant women with severe COVID-19 are at high risk for intensive care unit (ICU) admission and adverse maternal outcomes. Evidence on the burden and impact of bacterial infections in this group is limited.

We conducted a single-center retrospective cohort study of pregnant women with confirmed COVID-19 admitted for ≥ 48 h to the ICU of a referral maternity hospital in Isfahan, Iran, between June and December 2021. Clinical, demographic, microbiological, and outcome data were retrieved from electronic medical records. Bacterial isolates were identified and tested for antimicrobial susceptibility according to CLSI guidelines. Logistic regression was performed to determine factors independently associated with in-hospital mortality.

Of 527 pregnant women hospitalized with COVID-19, 71 required ICU admission and were included in the analysis. Bacterial infections were detected in 8 patients (11.3 %), most frequently caused by multidrug-resistant (MDR) Klebsiella pneumoniae. Compared with non-infected patients, women with bacterial superinfections had significantly longer hospital stays (22.4 vs. 10.2 days, p < 0.001) and ICU stays (16.8 vs. 5.2 days, p < 0.001), higher rates of invasive mechanical ventilation (50.0 % vs. 9.5 %, p = 0.002), and increased mortality (37.5 % vs. 9.5 %, p = 0.025). Univariate analyses identified bacterial superinfection, MDR pathogens, carbapenem/vancomycin use, lower admission SpO₂, and carbapenem-resistant K. pneumoniae as predictors of death. In multivariate analysis, only bacterial superinfection (aOR = 13.35, 95 % CI: 1.05-170.06) and lower oxygen saturation at admission (aOR = 1.21 per 1 % decrease, 95 % CI: 1.06-1.38) remained independent predictors of mortality.

Bacterial superinfections, especially with multidrug-resistant pathogens, are relatively common in ICU-hospitalized pregnant women with COVID-19 and strongly linked to worse outcomes, including higher mortality. Early detection, infection control, and rational antibiotic use are essential to improve survival.