Fetal left kidney at 28 weeks of pregnancy may be unclear due to the position of the fetus, which may not be clearly seen on the imaging or the fetus may have a pathological condition such as renal agenesis. Generally speaking, if the left kidney is not clear, the doctor may not be able to detect it due to the position of the fetus during the examination, so it is recommended to move around appropriately and review the examination again. If the left kidney is still not detected after repeated checkups, then the left kidney may be absent, which needs to be taken seriously, and further examination is recommended to see if there is any chromosomal abnormality, and prenatal checkups are needed to see how to treat the next step. If abnormalities are found during the labor and delivery test, then timely medical attention is recommended.