Effective anatomical and functional status of the lower uterine segment at term: estimating the risk of uterine dehiscence by ultrasound

Fertil Steril. 2013 Feb;99(2):496-501. doi: 10.1016/j.fertnstert.2012.10.019. Epub 2012 Nov 3.

Abstract

Objective: To define the role of lower uterine segment (LUS) evaluation at term.

Design: Observational case-control study.

Setting: University hospital.

Patient(s): Ninety-four patients were divided into two groups. Group A consisted of 45 multiparous single fetus pregnant women with up to two previous cesarean sections (CS). Group B consisted of 49 multiparous pregnant women with up to three vaginal deliveries and no uterine scars.

Intervention(s): Total LUS and myometrial thickness were measured by sonogram in all patients before undergoing a CS.

Main outcome measure(s): The primary outcome is a correlation between echographic measurements and features of the LUS at the time of CS. The secondary outcome is a definition of a correlation between the number of previous CS, interdelivery interval time, and features of the LUS (grades I-IV).

Result(s): Sonographic measurements revealed significant differences in LUS size and myometrial thickness between the two groups. Grades III and IV of LUS were only observed in group A. An interdelivery interval <18 months, LUS thickness ≤ 3.0 mm, and myometrial thickness < 1.5 mm were statistically significant predictors of LUS grades III and IV. Number of previous CS showed no correlation with surgical LUS status.

Conclusion(s): Sonographic evaluation of the LUS may be a noninvasive, reproducible, and safe technique for defining the risk of uterine dehiscence, with a sensitivity of 100% and specificity of 85% (positive predictive value, 45%; negative predictive value, 100%).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Case-Control Studies
  • Cesarean Section / adverse effects*
  • Female
  • Humans
  • Parity
  • Pregnancy
  • Pregnancy Complications / diagnostic imaging*
  • Pregnancy Complications / etiology
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Surgical Wound Dehiscence / diagnostic imaging*
  • Surgical Wound Dehiscence / etiology*
  • Ultrasonography
  • Uterine Diseases / diagnostic imaging*
  • Uterine Diseases / etiology*
  • Vaginal Birth after Cesarean
  • Young Adult