Exam

Fetal Presentation

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Fetal Presentation, Fetal Attitude, Asynclitism

  • Presentation
  • Breech (Head is not presenting part)
  1. Occurs in 25% of pregnancies at 30 weeks
  2. Abnormal after 32 weeks
  3. See Fetal Malpresentation
  • Presentation
  • Cephalic (Head is presenting part)
  1. Normal Presentation: Vertex
    1. Normal Attitude: Fetus is in full flexion
    2. Every fetal joint is flexed
    3. Smallest fetal head diameter: Suboccipitobregmatic
  2. Abnormal presentations: Extended Attitude
    1. General
      1. Abnormal Attitude: Fetal head is extended
      2. Results in largest head diameter: Occipitomental
      3. Increases diameter 3 cm (24%) over flexed head
      4. May results in Failure to Progress
    2. Face Presentation
    3. Brow Presentation
    4. Shoulder Presentation
  3. Abnormal Presentation: Asynclitism
    1. Definition
      1. Lateral flexion of head
      2. Sagittal Suture not in midline of vaginal canal
    2. Interpretation
      1. Mild Asynclitism is normal
      2. Extreme Asynclitism interferes with delivery
        1. May result in Failure to Progress
        2. Interferes with forceps application