Among them, we should mention both extremes of maternal age, either in adolescent mothers (age under 17 years) or in older mothers (age above 35 years) [7,12], mothers’ smoking habits [13], vaginal bleeding in the first or second trimester, as well as bleeding due to placental abruption or placenta previa [14], fetal gender, and of course, genetic predisposition for sPTB [15,16], including personal [17,18] and family history [19,20] of sPTB. The gene discussed is SPTB; the disease is placenta praevia.