aims to determine the accuracy of measurement of the LUS thickness by trans-abdominal and transvaginal ultrasound at term pregnancy in comparison to the actual thickness of LUS measured with manual caliper measurement during cesarean delivery.

Study hypothesis: In women with previous cesarean delivery, determination of the LUS thickness can be done by trans-abdominal and transvaginal ultrasound at term pregnancy and compared to the actual thickness of LUS measured with a manual caliper at cesarean delivery.

Study question: considering transabdominal & transvaginal ultrasound, which of them would be more accurate in the assessment of LUS thickness?

Inclusion Criteria:

• Age (20:40 years old).
• Women at term (37:40 weeks).
• With singleton pregnancy.
• Presenting by vertex (cephalic presentation).
• Having adequate liquor.
• Previous delivered by cesarean delivery one time.

Exclusion Criteria:

• Fetal malformations, e.g fetal hydrops.
• Uterine malformations, e.g bicornuate uterus.
• Placental malformations, e.g placenta praevia, placenta accrete.
• Uterine surgery is other than a cesarean, e.g myomectomy.
• Women in labor (painful, regular uterine contractions, cervical dilatation, tender scar, and discomfort is not stopped by sedation).
• Obese patients (BMI >30 kg/m2)

130 pregnant women at term with a previous one cesarean section admitted for an elective cesarean delivery will be enrolled. LUS thickness will be measured using both TVS and TAS prior to the cesarean. The actual thickness of the LUS will be measured using a sterile metal ruler before the neonate had been delivered.