Fetal maturity grade 0 generally refers to placental maturity grade 0, which suggests that the placenta is immature, and a correct assessment of placental function can help assess the intrauterine condition of the fetus and prevent adverse pregnancy outcomes. Fetal maturity in clinical practice mostly refers to placental maturity, so fetal maturity grade 0 generally refers to placental maturity grade 0, a term commonly used in ultrasound. Placental maturity on ultrasound is generally categorized into four grades: grade 0, grade 1, grade 2, and grade 3, with higher grades indicating higher maturity. Placental maturity level 0 indicates that the placenta is immature and functioning well, while placental maturity level 3 indicates that the placenta is aging and functioning poorly. Under normal circumstances, placenta maturity level 0 is the normal performance before 28 weeks of pregnancy. If the ultrasound before 28 weeks of pregnancy indicates that the placenta has high maturity level, it suggests that the placenta has matured in advance, and the function of the placenta may be declining prematurely, so it is necessary to do a good job of obstetrics under the guidance of professional doctors. It is necessary to pay attention to the development of the fetus in the uterus to prevent adverse pregnancy outcomes such as intrauterine fetal death due to placental failure and intrauterine hypoxia.