Amniotic fluid depth of 81mm in 25 weeks of pregnancy is considered excessive. The depth of amniotic fluid between 30-80mm in mid-pregnancy is normal, and the vertical depth of the largest dark area of amniotic fluid is greater than or equal to 8cm, diagnosing amniotic fluid excess, and between 8-11 for mild amniotic fluid excess, so the depth of amniotic fluid in 25 weeks of pregnancy, 81mm, is considered to be mild amniotic fluid excess. Among pregnant women with excess amniotic fluid, the cause is unknown in about 1/3 of the cases. Significant excess amniotic fluid may be associated with factors such as fetal structural abnormalities, pregnancy co-morbidities and complications. Therefore, if the depth of amniotic fluid is 81mm in the 2nd week of pregnancy, it is recommended to consult a professional obstetrician, ask for a detailed medical history, carefully examine the fetus with ultrasound, clarify whether the fetus has any combination of other structural abnormalities and genetic diseases, etc., and decide whether to continue the pregnancy based on the combination of conditions. Regular checkups during pregnancy are recommended for timely detection and treatment of problems.