PTGS2 and fetal growth restriction: To hypothesize that the overexpression of PTGS2 was associated with the above PE and IUGR conditions, we selected a flavonoid compound library to investigate its in silico inhibitory effects and compared it with those of the different PTB drugs (ritodrine, hydroxyprogesterone caproate, retosiban, terbutaline, and allylestrenol) used to treat PTB.