Hypertensive disorders during pregnancy are significant contributors to maternal mortality and morbidity globally, with preeclampsia (PE) being one of the main condition − affecting 3 % to 6.5 % of pregnancies worldwide [1], [2], [3]. This situation has been further complicated by the COVID-19 pandemic [4], [5], [6]. As pregnant individuals are at higher risk for severe SARS-CoV-2 infection compounded by pre-existing conditions such as chronic hypertension, COVID-19 has led to heightened maternal and perinatal morbidity and mortality compared to the general population [7], [8].

Associations between COVID-19 and PE have been identified in unvaccinated women, showing increased occurrence of PE among COVID-19 cases and higher maternal and perinatal related-morbidity [9], [10], [11]. These reports suggest an increased risk for PE in pregnant women diagnosed with COVID-19 [12]. A cohort study demonstrated that most unvaccinated pregnant women who developed severe pneumonia due to SARS-CoV-2 also exhibited PE features, unfolding a PE-like syndrome induced by severe COVID-19 [13]. This association is grounded on the similar pathophysiology and clinical presentation of PE and COVID-19, underscoring the unique interplay of SARS-CoV-2 during pregnancy [14], [15], [16], [17], [18].

PE is characterized by multisystemic organ involvement, inflammation, and endothelial damage, with eclampsia and HELLP syndrome as its most severe forms. Key biomarkers like soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) are used as predictors, with increased sFlt-1 and decreased PlGF correlating with disease onset [19], [20], [21]. The sFlt-1/PlGF ratio up to 38 cutoff can provide reassurance for the absence of PE at that given time, as well as it indicates that the development within the following week is very unlikely; staring a potential prediction value for clinical interpretation and management [22]. COVID-19 presents similar challenges for reassuring prognosis, because it is associated with multi-organ involvement and extensive inflammation, making differential diagnosis difficult, especially in SARS-CoV-2 unvaccinated severe cases where a PE-like syndrome can occur [13], [23]. Therefore, alongside a similar clinical presentation in severe cases, SARS-CoV-2 infection, like PE, can disrupt placental biomarker balance and alter renin-angiotensin system homeostasis [18], [24]. However, the sFlt-1/PlGF ratio has proven effective in distinguishing true PE cases within COVID-19-positive SARS-CoV-2 unvaccinated pregnant cohorts, highlighting the importance of these biomarkers in managing pregnancy complications [12], [25]. Hence, accurate diagnosis of PE, with consideration of biomarkers, is pivotal for clinical intervention, particularly in cases potentially leading to preterm births. Timely delivery decisions significantly influence perinatal outcomes, highlighting the utility of PE biomarkers in guiding management, particularly in COVID-19 cases [25], [26].

With the robust intervention of SARS-CoV-2 vaccination among pregnant and postpartum women, the clinical severity of COVID-19 has decreased, reducing severe cases and maternal deaths as vaccination rates increase [27], [28], [29], [30]. Concomitantly, the establishment of new viral variants with more robust ecological fitness but with lower virulence characteristics replaced previously established SARS-CoV-2 Variants of Concern (VOCs), alleviating some of the burden associated with the disease [31], [32]. Observing the evolving landscape of COVID-19 within SARS-CoV-2 vaccination and its implications for high-risk pregnancies with hypertensive disorders, it is key to expand the understanding of the consequences of COVID-19 and the extend evaluation on the association of COVID-19 and PE [18]. Thus, this study aimed to assess maternal and perinatal outcomes and PE biomarkers sFlt-1 and PlGF serum levels and temporal dynamics in pregnant women with hypertensive disorders after implementing vaccination against COVID-19, comparing cases with and without a history of confirmed SARS-CoV-2 infection during pregnancy.