GSTM1 and COVID-19: UC: umbilical cord; SD: standard deviation; CI: confidence interval; p-value: probability value; cm: centimeters: R/R: respiratory rate; min: minute; O2: oxygen; %: percentage; Hb: hemoglobin; g/dl: grams per deciliter; WBC: white blood cells; μl: microliters; RBCs: red blood cells; PCV: packed cell volume; MCV: mean corpuscular volume; fl: femtoliters; IgG: immunoglobulin G: COVID-19: coronavirus disease-19