Pregnant women with fluid dark area 20mm is not necessarily serious, depending on the part of the fluid dark area occurs different mainly manifested in the following two situations; 1. fluid dark area in the uterine cavity: generally refers to the uterine cavity fluid, under normal circumstances, the uterine cavity of pregnant women will not appear fluid, liquid dark area below the gestational sac, commonly blood accumulation, may suggest that pregnant women have a pre-eclampsia miscarriage, at this time should be actively engaged in the treatment of fetal preservation. 2. Pelvic fluid: pregnant women pelvic fluid dark area 20mm, if there is no lower abdominal pain, lumbago, vaginal bleeding and other symptoms, ultrasound examination of the uterine gestational sac is well developed, the impact on the fetus is not great, do not need special treatment. Pregnant women with fluid dark area 20mm if accompanied by abdominal pain and other discomforts, you need to go to the hospital in time.