hpl refers to human placental prolactin, a single-chain polypeptide hormone produced, stored, and released by placental syncytiotrophoblast cells. hPl can be measured in the blood of pregnant women from the 5th week of gestation, and as pregnancy progresses, the level of hPl gradually rises, generally reaching a peak before delivery and rapidly declining after delivery. The level of hPl concentration is related to the size of the placenta, which can indirectly reflect the growth and development of the fetus: 1. Values in the normal range: usually indicates that the fetus is growing and developing well in the uterus. 2. Low value: for pregnant women before 28 weeks of pregnancy, there is a possibility of preterm labor; for pregnant women after 28 weeks of pregnancy, there is a possibility of preterm labor; for the small weight of the fetus, it suggests that there is growth restriction. 3. Higher values: generally associated with twin pregnancies, mother-child blood group incompatibility, overdue pregnancies, giant babies, etc. If the mother has gestational diabetes, hpl will also increase. For pregnant women with abnormal hpl, it is recommended that they go to the obstetrics and gynecology department of a regular hospital, complete the ultrasound, fetal heart monitoring and other tests, and then take active treatment under the guidance of the doctor after clarifying the cause of the disease.