Association between coronavirus 2 infection and preeclampsia among unvaccinated women

To investigate the association between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2/COVID-19) infection and preeclampsia (PE); to verify whether the strength of the association differs according to the infection onset (trimester of pregnancy).

Retrospective cross-sectional study. Included women giving birth at a public hospital in Brazil from July 2020 to January 2021. All women were offered testing for COVID-19 during birth; they were also offered to test during prenatal care if symptomatics or contactants. Excluded women not tested. Compared the frequency of PE as well as of PE superimposed to chronic hypertension (PESCH) in women with versus without infection. Associations were accessed using bivariate and multivariable logistic regression analysis.

Among 1,575 women included, 288 (18.3%) had infection, 53 (3.4%) had PE, and 32 (2.1%) had PESCH. In univariate analysis, infection was significantly associated with PE, but not with PESCH. We then considered only PE as the outcome. The multivariable model included PE, infection, primigravida, fewer than seven prenatal visits. We found association between infection and PE, adjusted odds ratio 2.1; p=0.017. Women infected in the first trimester had a higher frequency of PE than those with infections in the second/third trimester, suggesting a temporal sequence, but the difference wasn't significant (p=0.054).

Our data suggests association between SARS-CoV-2 infection and PE without chronic hypertension. The greater frequency of PE in women who had infection in the first trimester suggests a temporal sequence, but the small numbers are a limitation. Studies with larger samples are welcome.