A resident is counselling women planning future pregnancies about the risk of uterine rupture during a subsequent labour, stratified by the type of prior uterine incision. The approximate risk of symptomatic uterine rupture during labour after a prior classical cesarean section, compared with a prior low transverse incision, is closest to:

• A 1 to 2 percent versus 0.1 percent
• B 4 to 9 percent versus 0.5 to 1 percent ✓
• C 10 to 15 percent versus 2 to 3 percent
• D Less than 0.5 percent versus 5 percent

Explanation

A prior classical incision through the contractile upper uterine segment carries roughly a 4 to 9 percent risk of uterine rupture during labour, while a prior low transverse segment incision carries only about 0.5 to 1 percent, which is why classical scars mandate elective repeat cesarean. Option A understates the classical risk, and option D inverts the relationship entirely.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.