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.
The grading system is as follows:
grade 0: 30 weeksgrade 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 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