Placental grading

Placental grading (Grannum classification) refers to a ultrasound grading system of the placenta based on its maturity. This primarily affects the extent of calcifications. In some countries the use of placental grading has fallen out of obstetric practice due to a weak correlation with adverse perinatal outcome 5.

The grading system is as follows:

  • grade 0: <18 weeks
  • grade I: 18-29 weeks
    • occasional parenchymal calcification/hyperechoic areas
    • subtle indentations of chorionic plate
  • grade II: >30 weeks
    • occasional basal calcification/hyperechoic areas
    • deeper indentations of chorionic plate (does not reach up to basal plate)
      • seen as comma type densities at the chorionic plate
  • grade III: >39 weeks
    • significant basal plate calcification
    • chorionic plate interrupted by indentations (frequently calcified) that reach up to basal plate: cotyledons
    • an early progression to a grade III placenta is concerning and is sometimes associated with placental insufficiency
      • associated with smoking, chronic hypertension, SLE, diabetes 
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Article information

rID: 13909
Tag: cases
Synonyms or Alternate Spellings:
  • Placental sonographic grading
  • Placental ultrasound grading
  • Placental maturity grading
  • Grannum classification

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    Case 1: grade III placenta
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