A 30-year-old primigravida at 38 weeks has a prolonged second stage (3 hours without descent despite pushing). Fetal head is at +2 station, OA position, CTG is reassuring. Vacuum delivery is planned. Which of the following is an absolute contraindication to vacuum-assisted delivery?
- A Occipito-posterior fetal position
- B Maternal BMI >35 kg/m²
- C Prior failed forceps application at the same delivery
- D Gestational age 34 weeks ✓
Explanation
Vacuum extraction is contraindicated before 34 weeks gestation because the fetal calvarium is too soft and poorly ossified, making scalp avulsion, cephalhaematoma, and intracranial haemorrhage highly likely. Most guidelines (RCOG, ACOG) cite gestational age <34 weeks as an absolute contraindication. Occipito-posterior position, maternal obesity, and prior failed forceps are relative considerations or contraindications for sequential instrument use, but not absolute contraindications to vacuum per se. Sequential instrument use (failed forceps then vacuum or vice versa) significantly increases neonatal injury risk.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.