When performing vacuum-assisted delivery (VAD), which of the following represents a 'pop-off' (cup detachment) scenario that should prompt abandonment rather than reattempt?

• A First cup detachment at 40 minutes, after which maternal pushing has been suboptimal
• B Second cup detachment during a single contraction despite maintained traction axis and adequate vacuum pressure ✓
• C First cup detachment occurring during maternal pushing effort, with cervical tissue accidentally caught at cup edge
• D Cup detachment at maximum vacuum of 0.8 kg/cm² with fetal head at +2 station after 2 contractions

Explanation

RCOG and WHO guidelines stipulate that vacuum delivery should be abandoned after three pop-offs OR if delivery has not been achieved within a specified number of contractions (typically 3 with descent) or time. A second cup detachment during the same contraction despite correct technique suggests the head is not descending as expected, possibly indicating CPD or malpresentation, and proceeding risks scalp injury (cephalhematoma, subgaleal hemorrhage) disproportionate to benefit. Option A: first pop-off with maternal pushing issue is not itself an indication to abandon; correcting pushing technique is appropriate. Option C: catching maternal tissue is a technique error to correct, not necessarily abandon. Option D: described parameters are within normal for appropriate VAD.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.