PGF and COVID-19: Pooled analysis of the sFlt-1/PlGF ratio between COVID-19 asymptomatic vs. symptomatic patients varied and amounted to 49.3 ± 35.7 vs. 37.1 ±25.6 (SMD = 0.30; 95% CI: −0.35 to 0.95; p = 0.36).