Background: The vacuum extractor is being increasingly advocated as the instrument of first choice for assisted vaginal delivery. It is widely believed that the vacuum cup will dislodge before causing serious fetal trauma.
Case: Rotational delivery of a term infant was effected using a vacuum extractor. A 6-cm Malmström metal cup with a paramedian application was in place for 12 minutes. The vacuum pressure developed was 0.8 kg/cm2. Four traction efforts with contractions were required to deliver the fetal head. A neonatal skull x-ray the following day showed a comminuted parietal bone fracture at the vacuum cup application site. Management was conservative, and the infant's neurologic behavior remained normal.
Conclusion: The vacuum extractor exerts considerable traction force. Fetal skull fracture can result, and its true incidence may be higher than expected, considering that few neonates with normal neurologic behavior undergo skull x-ray.