Variations of cervical head entrapment in vaginal breech births: New insights on how to prevent, manage and resolve.

This paper presents a novel, systematic way to understand the causes of cervical head entrapment in vaginal breech births, and new insights into management. Three different types of cervical head entrapment are described, with detailed illustrations: unpredictable and potentially catastrophic, manageable, and preventable. The first affects preterm and growth-restricted fetuses. The second involves some degree of uterine prolapse. The third may result from prolonged head entrapment at the pelvic inlet, leaving time for cervical contraction or oedematous entrapment. Traditional and innovative strategies to resolve and prevent this complication are described and illustrated, with suggestions for further research.