When the fluid in the uterine cavity has not been absorbed at 16 weeks of pregnancy but the fetus is well developed, it can be observed temporarily, but if there are symptoms such as vaginal bleeding, it is necessary to give birth control treatment. Ultrasound examination at 16 weeks of pregnancy suggests that there is fluid in the uterine cavity that has not been absorbed, when the ultrasound examination suggests that the fetus is developing well and there are no symptoms, it can be temporarily observed, no special treatment is needed, and dynamically observe the fluid situation, usually it will be slowly absorbed by itself. If the fluid in the uterine cavity is combined with vaginal bleeding and other symptoms, it is necessary to follow the doctor’s advice to rest properly, if necessary, to give medication to protect the fetus, and at the same time, avoid sexual life and strenuous exercise, and observe the changes in the fluid. In the middle of pregnancy, follow the doctor’s advice to increase food rich in protein, iron, calcium and vitamins and other nutrients to meet the needs of fetal development. When symptoms such as vaginal bleeding and other symptoms of preeclampsia occur, it is necessary to go to the hospital in time to consult a doctor, and if necessary, keep the fetus on treatment. If the ultrasound examination at 16 weeks of pregnancy indicates that there is fluid in the uterine cavity that has not been absorbed, it is necessary to treat the symptoms under the guidance of the doctor.