Pelvic inlet, mid pelvis, and pelvic outlet

  • Plane of the pelvic inlet - between the greater and lesser pelvis, it marks is the superior aperture of the pelvis.
  • Plane of the mid pelvis (midplane, plane of the obstetric outlet - the plane of the least pelvic dimensions) - between the lower border of the pubic symphysis, the ischial spines, and the tip of the sacrum.
  • Plane of the pelvic outlet (plane of the anatomical outlet) - marks the inferior aperture of the pelvis.

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