Imbalanced Angiogenesis in Pregnancies Complicated by SARS-CoV-2 Infection

COVID-19 and preeclampsia (preE) share the ANG-II mediated endothelial dysfunction, resulting from a significant dysregulation of RAS and an imbalanced proportion of anti-angiogenic and pro-angiogenic soluble plasmatic factors. Of note, an increased incidence of preE has been reported among COVID-19-infected mothers compared to the general pregnant population. The two most promising angiogenic markers are the soluble fms-like tyrosine kinase receptor-1 (sFlt-1), the major antiangiogenic factor, and the placental growth factor (PlGF), a powerful angiogenic factor. Since these markers have proven useful in the prediction, diagnosis, and severity of preE, this study aimed to evaluate their maternal serum levels in pregnancies complicated by SARS-CoV-2 infection and to assess their potential use to guide the management of these women. A retrospective analysis of SARS-CoV-2-positive pregnant women was performed. The serum levels of sFlt-1 and PlGF were collected at the diagnosis of SARS-CoV-2 infection at the hospital, before the beginning of steroid/hydroxychloroquine and/or antithrombotic therapy. The sFlt-1/PlGF ratio was stratified using cut-off values clinically utilized in the diagnosis and prediction of preE (low < 38, intermediate 38−85/110* and high >85/110*, * if before or after the 34th week of gestation). A total of 57 women were included, of whom 20 (35%) had signs and symptoms of COVID-19 at hospital presentation and 37 (65%) were asymptomatic. None were vaccinated. The mean gestational age at diagnosis of SARS-CoV-2 infection was 32 weeks in symptomatic patients and 37 weeks and 5 days in asymptomatic ones (p = 0.089). sFlt-1 serum levels were higher in SARS-CoV-2 positive asymptomatic patients compared to women with COVID-19 related symptoms (4899 ± 4357 pg/mL vs. 3187 ± 2426 pg/mL, p = 0.005). sFlt-1/PlGF at admission was <38 in 18 of the 20 symptomatic women (90%) compared to 22 (59%) of the asymptomatic patients (p = 0.018). Of note, two of the three women admitted to the intensive care unit had a very low ratio (<2). In turn, rates of patients with sFlt-1/PlGF at admission > 85/110 were not significantly different between the two groups: 11% in asymptomatic patients (4/37) vs. none of the symptomatic patients (p = 0.286), and all of them presented a placental dysfunction, like preE (n = 1) and FGR (n = 3). Of note, there were no stillbirths or maternal or neonatal deaths among symptomatic patients; also, no cases of preE, FGR, or small for gestational age neonates were diagnosed. In conclusion, our data suggest that SARS-CoV-2 infection during pregnancy could influence the angiogenic balance. A significant pathological alteration of the sFlt-1/PlGF ratio cannot be identified during the symptomatic phase; however, if left untreated, SARS-CoV-2 infection could potentially trigger placental dysfunction.