TITLE:
Ultrasound Evaluation of Caesarean Scar of Prelabour and Labour Caesarean Sections: A Cross Sectional Analytical Study
AUTHORS:
Nisansala Perera, Thiran Dias
KEYWORDS:
Caesarean Section Scar, Residual Myometrial Thickness, Labour
JOURNAL NAME:
Open Journal of Obstetrics and Gynecology,
Vol.13 No.7,
July
31,
2023
ABSTRACT: Caesarean section is dramatically increased throughout the world in recent years. Rupture of the uterus is a devastating
complication in trial of labour following previous Caesarean section. Evidence
suggests that the size of the uterine scar and the residual myometrial thickness
(RMT) are associated directly with the risk of uterine rupture and risk of dehiscence
in subsequent deliveries. Impact of the prelabour and labour Cesarean section on
the RMT has not been studied in detail. Objectives: To compare RMT, Caesarean scar defects and to evaluate
the elasticity of the Caesarean scar between women who underwent prelabour and labour
Caesarean sections. Methods: This was a Cross sectional analytical study. Women who underwent Caesarean section in their first pregnancy
were recruited. Sample was stratified to prelabour and labour Caesarean section groups. Transvaginal ultrasound scan was performed
six months following the Caesarean section. Dimensions of the uterus, uterine scar
defect, RMT and elastosonography of the uterine scar were assessed. Results: A total of 240 postpartum women were analyzed. Uterine
niche was detectable in 194 subjects. Prelabour CS group had demonstrated 91.7%
(n = 110) scar defects (uterine niche) out of 120 cases and the rate among labour
CS group was 70% (n = 84). There was a significant difference in the presence of
uterine niche among 2 groups as Prelabour group was found to have more scar defects
(p mm (SD 1.2) and 4.99 mm (SD 1.3) respectively and there was no significant
difference (t = 0.38, p = 0.71). There was no significant difference between the
dimensions of the uterine CS defects of the studied groups. Prelabour CS group had
significantly higher Target strain [0.28 vs. 0.24 (t = 2.12, p = 0.04)] and significantly
less strain ratio [1.45 vs. 1.55 (t -2.42, p = 0.04)] than labour CS group indicating
a better scar in prelabour group. Conclusion: There was no significant difference in RMT and uterine
scar defects between prelabour and labour Caesarean section groups. But prelabour Caesarean
section scars were less stiff than labour Caesarean section scars. Further studies
are warranted to elaborate on the association.