The DECISION trial investigated preterm birth in women with a previous caesarean scar thickness ≤2.5 mm. Its primary clinical recommendation was:
- A Lower uterine segment thickness alone is insufficient to indicate elective caesarean before 39 weeks ✓
- B All women with scar thickness <2.5 mm should deliver at 34 weeks
- C Scar dehiscence risk doubles for every 0.5 mm reduction below 3.5 mm
- D MRI measurement of scar should replace ultrasound for predicting rupture risk
Correct answer: A. Lower uterine segment thickness alone is insufficient to indicate elective caesarean before 39 weeks
Explanation
The evidence base from multiple trials including the TOLAC literature demonstrates that lower uterine segment thickness (LUST) measurement by ultrasound, while a marker of potential scar weakness, has poor positive predictive value for actual uterine rupture and cannot alone justify early elective delivery before 39 weeks. Routine measurement is not recommended as a decision tool for timing of elective caesarean. Clinical context, indication for prior caesarean, and maternal risk factors must all be integrated.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.