Vol 92, No 5 (2021)
Research paper
Published online: 2021-03-17

open access

Page views 1205
Article views/downloads 1103
Get Citation

Connect on Social Media

Connect on Social Media

Two- and three-dimensional transvaginal ultrasound in assessment of the impact of selected obstetric risk factors on cesarean scar niche formation: the case-controlled study

Joanna Budny-Winska1, Aleksandra Zimmer-Stelmach1, Michal Pomorski1
Pubmed: 33757154
Ginekol Pol 2021;92(5):378-382.


Objectives: Incomplete healing of the uterine scar after cesarean section may result in formation of a niche. The aim of this study is to identify the potential risk factors for the improper uterine healing after cesarean section in women with single layer, full thickness uterine closure with the use of two- and three-dimensional transvaginal ultrasonography.
Material and methods: 204 women with a history of at least one low transverse cesarean section (CS) with a single layer uterine closure participated in the study. Residual myometrial thickness (RMT), adjacent myometrial thickness (AMT), width (W), depth (D) and volume of the niche, RMT/AMT, RMT/D, RMT/W ratio and clinical characteristics were analyzed.
Results: A niche after cesarean section was found in 153 cases. However only five patients had a RMT < 2.2 mm, and 35 had an RMT/AMT ratio ≤ 0.5. The RMT and RMT/AMT ratio among women who had undergone more than one cesarean section was lower than among women who underwent the first cesarean section. No statistically significant relationship was found between the incidence of niche, its parameters and cervical dilation, uterine contractions, cesarean section in the second stage of labor, type of uterus incision expansion and flexion, operator’s experience.
Conclusion: Healing of the uterine cesarean section scar in women with single-layer continuous suture covering the entire thickness of the myometrium, excluding the decidua is not affected by the mode of caesarean section, type of uterine incision expansion and flexion, operator’s experience, stage of labor at the time of caesarean section.

Article available in PDF format

View PDF Download PDF file


  1. Wang CB, Chiu WW, Lee CY, et al. Cesarean scar defect: correlation between Cesarean section number, defect size, clinical symptoms and uterine position. Ultrasound Obstet Gynecol. 2009; 34(1): 85–89.
  2. Pomorski M, Fuchs T, Rosner-Tenerowicz A, et al. Sonographic evaluation of surgical repair of uterine cesarean scar defects. J Clin Ultrasound. 2017; 45(8): 455–460.
  3. Osser OV, Jokubkiene L, Valentin L. High prevalence of defects in Cesarean section scars at transvaginal ultrasound examination. Ultrasound Obstet Gynecol. 2009; 34(1): 90–97.
  4. Donnez O, Donnez J, Orellana R, et al. Gynecological and obstetrical outcomes after laparoscopic repair of a cesarean scar defect in a series of 38 women. Fertil Steril. 2017; 107(1): 289–296.e2.
  5. Jordans IPM, de Leeuw RA, Stegwee SI, et al. Sonographic examination of uterine niche in non-pregnant women: a modified Delphi procedure. Ultrasound Obstet Gynecol. 2019; 53(1): 107–115.
  6. Pomorski M, Fuchs T, Zimmer M. Prediction of uterine dehiscence using ultrasonographic parameters of cesarean section scar in the nonpregnant uterus: a prospective observational study. BMC Pregnancy Childbirth. 2014; 14: 365.
  7. Vikhareva Osser O, Valentin L. Clinical importance of appearance of cesarean hysterotomy scar at transvaginal ultrasonography in nonpregnant women. Obstet Gynecol. 2011; 117(3): 525–532.
  8. Ofili-Yebovi D, Ben-Nagi J, Sawyer E, et al. Deficient lower-segment Cesarean section scars: prevalence and risk factors. Ultrasound Obstet Gynecol. 2008; 31(1): 72–77.
  9. Chen Y, Han P, Wang YJ, et al. Risk factors for incomplete healing of the uterine incision after cesarean section. Arch Gynecol Obstet. 2017; 296(2): 355–361.
  10. Armstrong V, Hansen WF, Van Voorhis BJ, et al. Detection of cesarean scars by transvaginal ultrasound. Obstet Gynecol. 2003; 101(1): 61–65.
  11. Yazicioglu F, Gökdogan A, Kelekci S, et al. Incomplete healing of the uterine incision after caesarean section: Is it preventable? Eur J Obstet Gynecol Reprod Biol. 2006; 124(1): 32–36.
  12. Antila-Långsjö RM, Mäenpää JU, Huhtala HS, et al. Cesarean scar defect: a prospective study on risk factors. Am J Obstet Gynecol. 2018; 219(5): 458.e1–458.e8.
  13. Saad AF, Rahman M, Costantine MM, et al. Blunt versus sharp uterine incision expansion during low transverse cesarean delivery: a metaanalysis. Am J Obstet Gynecol. 2014; 211(6): 684.e1–684.11.
  14. Pomorski M, Fuchs T, Rosner-Tenerowicz A, et al. Standardized ultrasonographic approach for the assessment of risk factors of incomplete healing of the cesarean section scar in the uterus. Eur J Obstet Gynecol Reprod Biol. 2016; 205: 141–145.