Impact of trimester of infection on COVID-19 disease progression in pregnancy


      COVID-19 infection is associated with increased morbidity in pregnancy. We evaluate the effect of trimester of COVID-19 infection on disease progression in pregnant patients.

      Study Design

      This is a prospective cohort study of pregnant patients diagnosed with PCR-confirmed COVID-19 infection who delivered at a single urban hospital. Universal COVID-19 PCR testing was performed at hospital admission as well as for symptomatic patients in inpatient, emergency department and outpatient settings. Disease severity was determined by review of medical records and defined as asymptomatic, mild, moderate, severe, or critical based on National Institutes of Health (NIH) criteria. We evaluated disease progression from asymptomatic to symptomatic infection, stratified by trimester of COVID-19 diagnosis.


      From March 18, 2020 to May 31, 2021, 1092 pregnant patients were diagnosed with COVID-19, including 67(6%) first trimester, 309(28%) second trimester, and 716(66%) third trimester. There were no significant demographic differences between groups; 87% of patients in all trimesters were Hispanic. Among patients admitted within 14 days of a positive test, 2(15%) first trimester, 16(47%) second trimester, and 24(5%) third trimester patients were admitted for the indication of COVID-19 illness (Table 1). Across all trimesters, 993/1092(90.9%) of COVID-19 infections were asymptomatic or mild, and 35/345(10.1%) of asymptomatic patients developed symptoms. Of patients with asymptomatic or mild symptoms at diagnosis, 2/62(3.2%) first, 15/295(5.1%) second, and 36/689(5.2%) third trimester patients developed moderate, severe, or critical illness (p=0.79) (Table 2).


      Moderate, severe, or critical illness develops in almost 10 percent of pregnant patients. The frequency of COVID-19 disease progression in pregnancy does not differ by trimester of diagnosis.
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