A G2P1 at 32 weeks of gestation presents with premature rupture of membranes and recurrent late decelerations. The cervix is fully dilated, the vertex is at +2 station in occiput anterior position, and assisted vaginal delivery is planned. Why is vacuum extraction avoided in this situation?

• A Vacuum cups cannot maintain traction on the soft preterm scalp
• B Vacuum traction fails to rotate the persistently preterm vertex
• C Preterm fetuses have unossified fontanelles that prevent cup placement
• D Gestation below 34 weeks carries a high risk of subgaleal and intracranial haemorrhage ✓

Explanation

Vacuum extraction is generally contraindicated below 34 weeks because the preterm scalp has fragile bridging veins and an underdeveloped coagulation profile, giving a markedly increased risk of subgaleal haemorrhage and intraventricular haemorrhage. Forceps are the preferred instrument at this gestation. The other options describe mechanical problems that do not occur; the cup adheres well to a preterm scalp and fontanelle ossification is irrelevant to cup placement.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.