II. Definitions
- Brow Presentation
- Head hyperextended, with brow as presenting part
III. Pathophysiology
- Normal Attitude: Fetus is in full flexion
- Smallest fetal head diameter: Suboccipitobregmatic
- Brow Presentation is an extended attitude
- Results in largest head diameter: Occipitomental
- Increases diameter 3 cm (24%) over flexed head
- May results in Failure to Progress
IV. Epidemiology
- Incidence: 0.02% of singleton deliveries (1 in 1400 live births)
V. Causes
- Similar to Face Presentation
VI. Signs
- Digital cervical exam
- Forehead features palpable (anterior Fontanel, nose)
VII. Management
- Ceserean section required in most cases
- Brow Presentation rarely can deliver vaginally unless:
- Spontaneously converts to vertex or Face Presentation
- Fetus is very small or Pelvis is very large
- Do not attempt to convert Brow Presentation to vertex
- Never apply vacuum extractor to Brow Presentation
- Do not apply internal scalp electrodes
- Avoid Oxytocin
VIII. Complications
- Increased perinatal mortality: 1-8%