Purpose: Isthmocele or cesarean scar defect/niche and its consequences are becoming more common worldwide, which is unlikely to be because of improved diagnosis or rising cesarean rates. Objective: This study aimed to see how the development of niche and maternal problems were affected by the method of uterine incision extension. Subjects and Methods: A total of 280 women from Kasr Alainy Teaching Hospital's Labor and Delivery section were included in the study. Two groups were observed over 10 months: group A sharp extension group and group B blunt extension group (1:1). Results: There were no significant statistical differences between the two groups with respect to placental location, presentation, amniotic fluid, incision extension, and the presence of niche 6 weeks or 3 months postoperatively by transvaginal sonography. No significant differences were also found in scar thickness or surrounding myometrium thickness between the two groups. However, there were statistically significant variations between the two groups with respect to operational time, blood loss during closure, and uterine vascular damage. Conclusion: There was no difference in the establishment of a cesarean scar niche or scar thickness between sharp and blunt uterine incision extensions. Sharp incisions may be preferable to blunt incisions because they result in properly aligned myometrial layers. More clinical trials with bigger sample sizes are needed to assess the impact of the technique of extending the uterine incision on the establishment of cesarean niches.