Preeclampsia biomarkers (sFlt-1/PlGF) dynamics are not disrupted by SARS-CoV-2 infection during pregnancy in a hypertensive disorder SARS-CoV-2 vaccinated cohort.

Objectives: To analyze maternal and perinatal outcomes and serum levels of the preeclampsia (PE) biomarkers sFlt-1 and PlGF in pregnant women with hypertensive disorders vaccinated against SARS-CoV-2, with or without confirmed COVID-19 during pregnancy.

Methods: Multicenter (two-center) prospective cohort study secondary analysis. The cohort comprised pregnant women with hypertensive disorders who received SARS-CoV-2 vaccination, assessed from August 2021 to December 2022. Key variables included sociodemographic information, clinical background, maternal and perinatal outcomes, and biomarkers serum concentrations. A sFlt-1/PlGF ratio ≥ 38 was the threshold for predicting PE. The study compared outcomes based on the timing of SARS-CoV-2 infection and PE clinical onset.

Results: For biomarker analysis, 170 women provided serum samples: 31 had a confirmed COVID-19 during pregnancy, while 139 did not. Among these 170 women, 86 had chronic hypertension, and 100 developed PE. There were no significant differences in sociodemographic characteristics and gestational outcomes between the groups. The dynamics of the sFlt-1/PlGF ratio were similar regardless of COVID-19. Cesarean delivery was the most common delivery method in both groups, and there was a high rate of preterm births. No neonatal or maternal deaths were recorded.

Conclusions: The study suggests that pregnant women with hypertensive disorders who have been vaccinated against SARS-CoV-2 and subsequently infected show comparable maternal and perinatal outcomes and PE biomarker levels to those who were not infected. These results suggest that SARS-CoV-2 vaccination is protective for pregnant women, potentially reducing the association with a PE-like syndrome in severe cases of COVID-19 among those who are unvaccinated.