Placenta grades are number values assigned to a
placenta on the basis of its appearance on an ultrasound examination. They reflect the
placenta's age and level of maturation at the time of the exam and can provide
important information about when the baby is due. A placenta that matures too
quickly can be a cause for concern, as it may indicate a pregnancy complication
that could threaten the health of the developing fetus.
At each ultrasound session, the technician should note all findings in a report
that goes into the patient's chart.
The placenta anchors to the uterine wall during fetal development and provides
nutrition to the developing fetus. As the fetus grows, the placenta's
characteristics will change. It initially has a very homogenous appearance, but
will become dappled with dots and shadows over the course of the pregnancy.
Calcifications start to develop and will show up as white marks on the
ultrasound. The appearance of the placenta provides information about how old
it is, and placenta grades offer a uniform way for recording information.
Grade 0 : Placental body is homogeneous. The amniochorionic plate is even throughout. Late first trimester-early second trimester.
Grade I : Placental body shows a few echogenic densities ranging from 2-4 mm in
diameter. Chorionic plate shows small indentations. Mid second trimester
- early third trimester (18-29
wks).
Grade II : Chorionic plate shows marked
indentations,creating comma-like densities which extend into the placental
substance but do not reach the basal plate. The echogenic densities within the
placental also increase in size and number. The basal layer comes punctuated
with linear echoes which are enlarged with their long axis parallel to the
basal layer. Late third trimester (30 wks to delivery)
Grade III : Complete indentations of chorionic plate through to the basilar
plate creating cotyledons (portions
of placenta separated by the indentations) . (39 wks)
