GSTM1 and placenta praevia: The results showed that there was no significant difference in the umbilical cord around the neck, amniotic fluid index, and fetal heart before operation in the transfusion group, but the thickness of the anterior wall of uterus; the levels of Hb, PT, FIB, and TT in the transfusion group were lower than those in the nontransfusion group; and the number of placenta previa and the levels of PLT and APTT in the transfusion group were significantly higher than those in the nontransfusion group (P < 0.05).