What do grade 0, 1, 2 and 3 placenta mean?

The degree of the placenta is a value that represents the maturity process of the placenta throughout pregnancy. The placenta can be classified into four grades, between 0 and 3, which will depend on the gestational age and calcification of the organ.

Although it is a natural process, the maturation of the placenta may happen faster in some women, causing the degree to evolve quickly. In these cases, there is an increased risk of complications, such as premature birth or placental abruption, for example.

Ideally, the degree of the placenta should be assessed frequently by the obstetrician, who will be able to identify whether the placenta is aging too quickly and order other tests.

Degrees of maturity of the placenta

Placental maturation can be classified as follows:

• Placenta grade 0: It generally lasts until the 18th week and is characterized by a homogeneous placenta without calcification;
• Placenta grade 1: occurs between the 18th and 29th week and is characterized by a placenta with small intraplacental calcifications;
• Placenta grade 2: it is present between the 30th and 38th week and is characterized by a placenta with calcifications in the basal plate;
• Placenta grade 3: It is present at the end of pregnancy, around the 39th week, and is a sign of maturation of the baby’s lungs. Grade 3 placenta already presents calcification from the basal to the chorionic plate.

In some cases, early maturation of the placenta can be detected. It is not yet known exactly what could be causing it, but it is known that it is more common in very young women, women who are having their first pregnancy and pregnant women who smoke during childbirth.

Can the degree of the placenta interfere with pregnancy or childbirth?

The maturation of the placenta throughout pregnancy is a normal process and is not a cause for concern. However, if grade 3 placental maturation occurs before 36 weeks of gestation, this may be associated with a maternal-fetal condition.

When early maturation of the placenta is detected, the pregnant woman must be monitored more frequently and also during labor, to avoid complications, such as premature birth, placental abruption, heavy postpartum bleeding or low birth weight.

See how the placenta develops and find out what the most common changes are and what to do.

How the degree of the placenta is detected

The obstetrician can identify the degree of maturity of the placenta by observing the calcifications present during an ultrasound examination.