What Are Placenta Grades?

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.

Ultrasound technicians use placenta grades between zero and three when they write up the findings of an ultrasound examination. Zero refers to a placenta at the end of the first trimester and into the start of the second, when it has a uniform appearance and few, if any, calcifications. Grade four, the highest grade, appears at the end of the third trimester and indicates that the mother will deliver soon. The placenta is fully mature at this stage, and it will have a characteristic irregular appearance.

On an ultrasound, the technician should also check for any placenta problems like detachment from the uterine wall or placenta previa, where the placenta grows over the cervix. Sometimes these problems are less evident in the early stages of pregnancy, and thus the technician should take care to evaluate the placenta at every examination. She wants to identify any problems for the benefit of the patient and her doctor, as some issues may change the birth plan. If the ultrasound uncovers any concerns, the technician will want to talk to the patient's doctor, and the doctor will meet with the patient to discuss the situation.

Patients can ask about their placenta grades if they are curious. The ultrasound technician can point out the characteristics used in placenta grading. In training, ultrasound technicians see numerous sample images so they learn about what to look for when evaluating pregnancies. They also rely on their experience as practitioners to assign accurate placenta grades.