Pregnant women with liquid dark areas need prompt and absolute bed rest and avoid activities as much as possible. If the fetus is developing well, most of them can be absorbed slowly on their own. If necessary, the doctor will also need to treat the fetus on a case-by-case basis. The presence of a liquid dark area in pregnant women is mainly due to the separation of the wall of the fetal sac from the uterine wall, causing bleeding, which is a phenomenon of pre-eclampsia, and can usually be detected by ultrasound examination of the uterus. After the treatment of fetal preservation, it is necessary to closely observe whether the dark area of fluid is completely absorbed, if it is progressively enlarged, it is necessary to consider the abnormal development of the embryo, and if necessary, the pregnancy can be terminated. If the fetus is developing well, the fetal development should be closely monitored and regular obstetric examinations should be performed. In order to avoid the birth of abnormal fetus, Down’s syndrome screening and 4D ultrasound should be performed in time according to the gestational week.