Comparison of lower uterine segment thickness in 3rd trimester of pregnancy with and without previous caesarean section history

Abstract Objective: To compare lower uterine segment (LUS) thickness in third trimester of previous caesarean pregnancy with normal pregnancy. Methods: Women undergoing third-trimester sonographic examination, 50 with a history of LSCS and 50 with no history of cesarean delivery, were included for sonographic measurement of the lower uterine segment with a high-frequency probe. LUS was examined longitudinally and transversely to find areas of obvious uterine scar dehiscence. The calipers placed at the thinnest place so that the line of measurement had to be exactly perpendicular to the measured wall. Full LUS thickness was quantified with 1 cursor at the interface between urine and the bladder wall and another at the interface between amniotic fluid (or fetal scalp) and the decidua, P < .05 was considered significant. Results: The mean age participants was 25.78 years (SD = 3.87). The lower uterine segment was thinner in women with a previous cesarean delivery compared with normal group (mean ± SD, 3.140 ± 0.495 versus 4.096 ± 0.413 mm; P< .001) Conclusions: The lower uterine segment during a third-trimester sonographic examination is significantly thinner in women with a previous cesarean delivery.