Correlation between the Ultrasound Parameters of Uterine Scar after Cesarean Section and the Amount of Intraoperative Blood Loss in Patients with Cesarean Scar Pregnancy

  Objective  To analyze the correlation between ultrasound parameters of uterine scar after cesarean section and the amount of intraoperative blood loss in patients with cesarean scar pregnancy(CSP).

  Methods  A total of 35 CSP patients who received operational treatment from November 2011 to January 2013 were enrolled in this study. The 2-and 3-dimensional ultrasound examinations were performed before the surgery, and the following parameters were recorded:maximum diameter of lesion(D_max), average diameter of lesion(D_mean), implantation area of lesion(S), implantation volume of lesion(V), and implantation depth of lesion(D_imp). All these cases were divided into different groups according to the following characteristics separately:with/without fetal heart beat, lesion shown as gestational sac/mass, vasculature grade poor/median/rich, whetheror not combined with methotrexate(MTX) treatment prior to operations. The amount of bleeding during the operation was recorded. The correlation between the above parameters and the amount of intraoperative bleeding was analyzed. The bleeding amount of different groups was compared. Also, the patients were divided into two groups according to bleeding amount ≥ 200 ml and < 200 ml, and the potential independent risk factors of bleeding were analyzed using Logistic regression.

  Results  D_max and S had a linear correlation with bleeding amount (P=0.009 and 0.008). D_mean, V, and D_imp had no linear correlation with bleeding amount(P=0.017, 0.044, and 0.423, respectively). The difference of bleeding amount between groups with and without fetal heart beat was significant(23.38 ml vs 13.47 ml, P=0.004). There were no significant differences between groups of lesion types, color grades, and with/without MTX treatment(P=0.131, 0.044, and 0.047, respectively). The Logistic regression showed that S was an independent risk factor of operation bleeding amount(P=0.007), with an area under the receiver operating characteristic(ROC) curve of 0.839(0.606-1.071).

  Conclusions  The D_max and S of CSP as well as with/without fetal heart beat obtained from the 2-and 3-dimensional ultrasound have close correlations with the intraoperative bleeding amount in CSP patients. In particular, the S of the CSP is an independent risk factor for bleeding.