INTRODUCTION
Increasing rates of cesarean delivery (CD) in the world mean that a growing number of women are experiencing related complications.1 While short-term problems associated with the procedure include bleeding, and infection, there are also serious long-term issues, such as placenta adhesion anomalies, CD scar defects, uterine rupture, dehiscence, and caesarean delivery scar pregnancies. Further, many patients complain of postmenstrual spotting, dysmenorrhea, and pelvic pain, which may also be associated with these complications.2,3
There is no clear consensus on the best uterine closure technique for preventing cesarean scar defects. However, it is known that both the surgical suture technique and mechanical stresses affecting the surgical scar are the most important factors related to incision integrity.4 Several different techniques are used to close the uterus after cesarean, including single- and double-layer closures with/without locking and either passing through or avoiding the decidua. A variety of different suture materials are also available. Here, the main focus is on the uterine closure technique, especially for minimizing postoperative uterus rupture/dehiscence and caesarean delivery scar defects. Further, these techniques are modifiable parameters, with many recent studies having attempted to determine a standard.5 Nevertheless, no such standard has been established. For instance, while the Misgav Ladach single-layer continuous uterine closure with locking is prevalent throughout the world,6 studies have reported different results.7-10 A meta-analysis also showed a fourfold risk of uterine rupture in future pregnancies among patients whose uteri were closed using a single-layer locking technique when compared to those who were treated with a double-layer technique.11 Further, Stegwee et al. (2019) found that patients whose uterine incisions were closed by double-layer following cesarean section (CS) experienced greater advantages in terms of residual myometrium thickness (RMT), healing ratio (residual myometrium thickness/adjacent myometrium thickness), and dysmenorrhea.2 However, another meta-analysis conducted by Di Spiezio Sardo et al. (2017) found no significant differences between single- and double-layer closures in terms of niche development, uterine dehiscence, or rupture.10 As such, there is no current consensus about the specific uterine closure technique that best minimizes the risk of uterine rupture and/or caesarean delivery scar defect. This study therefore investigated the effects of single- and double-layer closures of the uterus in regard to niche development and residual myometrium thickness at 6-9 months after CS.