Placenta maturity is divided into four grades: 0, 1, 2 and 3.
The relationship with gestational age is as follows:
Grade 0: generally in the second trimester, about 12-28 weeks of pregnancy.
1 grade: generally, in the early stage of placental maturation, it can also deliver nutrition to the fetus with 30-32 weeks of pregnancy.
Grade 2: After 36 weeks of pregnancy, the placenta is close to Changshu.
Grade 3: Usually in the 37th or 38th week of pregnancy, indicating that the placenta has matured.
Note: If placental grade 3 is found before 37 weeks, combined with biparietal diameter and estimated fetal weight of 2,500 grams, premature placenta should be considered and the possibility of intrauterine growth retardation should be guarded.
Placental maturity is also related to diseases during pregnancy, which can be divided into two aspects: accelerating placental maturity and delaying placental maturity. The factors that accelerate placenta maturation are: pregnancy complicated with hypertension, nephropathy, pregnancy-induced hypertension syndrome and intrauterine growth retardation; The factors that delay placenta maturation are gestational diabetes mellitus and the incompatibility of RH factor between mother and fetus.