Background: The number of Cesarean sections (CS) is growing worldwide, intensifying the risk of complications in subsequent pregnancies and leading to increased maternal and fetal morbidity and mortality . In particular, the literature shows a higher risk of uterine rupture (UR) in subsequent pregnancy with trial of labor after cesarean section (TOLAC) Furthermore, there are few data about pre-labor UR in scarred uteri.
Objective: Since the key factor for management is timing, the aim of this study was to evaluate the accuracy of prenatal ultrasound (US) of scars in the early determining of pre-labor UR risk in women with a previous CS during their subsequent pregnancy.
Methods: From April 2014 to November 2018 a retrospective analysis was performed in order to evaluate the scar to vesicovaginal fold (VVF) distance in three patients with pre-labor UR and in 60 cases of the control group.
Results: The periconceptional CS scar-VVF distance in the three UR cases resulted significantly increased compared to the controls (23.7 ± 3.5 mm vs 2.3 ± 2.7 mm, p < 005); moreover, a time interval of less than 18 months and a previous pre-labor preterm CS were found as known risk factors.
Conclusion: In this study, a higher uterine incision due to placenta previa or isthmic myoma seems to be correlated with a major risk of UR. Therefore, periconceptional US examination of CS-VVF distance, (which represents the level of the previous CS), seems to be a useful predictive factor of pre-labor UR in subsequent pregnancies.
Keywords: Uterine rupture; antenatal care visit; obstetric emergency; placenta previa.