Our study group comprised 587 who gave birth to children following a previous cesarean section. Out of this group, 309 women delivered by a second cesarean section, and 278 delivered vaginally. There was no correlation between the dehiscence ratio and the period of time following the previous cesarean section. Before delivery we measured the thickness of the uterine scar following the previous cesarean section in 482 patients. Out of this group 249 patients delivered by a second cesarean section and 233 underwent natural labor. Among these patients we compared the resistance of the uterine scar during the following labor dependent of its ultrasound thickness. We noted that in scars under 3 mm of thickness (49 patients) the dehiscence of the scar occurred in 90% of patients (44 cases), and in scars above 3 mm of thickness (200 patients) the dehiscence of the scars was noted only in 13% of patients (26 cases). Thickening of the uterine scar is correlated with a decreased incidence of dehiscence. Out of 380 patients who underwent vaginal delivery, 240 received oxytocin at a dose of 2.5 j in 500 ml 0.9% NaCl. This groups ratio of dehiscence with and without the use of oxytocin was comparable. In patients undergoing labor, oxytocin use insignificantly increased successful vaginal delivery. The highest rate of dehiscence and paper-lower segments (43%) occurred in patients (with a previous cesarean section) delivering abdominally following an unsuccessful attempt at vaginal delivery.

Keywords: Cesarean Section, uterine scar, dehiscence, ultrasound, Oxytocin