Kidney is a very important organ in the human body, which is able to excrete all kinds of wastes in the human body. Kidneys are also an important organ to be examined during pregnancy. Generally speaking, the detection of kidneys is mainly through ultrasound to observe the part of kidneys, morphology and the width of renal pelvis. Most of the normal fetuses will be described as having both kidneys visible on the ultrasound list, that is, two kidneys can be seen in the fetus, but both kidneys are visible is only a kind of objective description, which has no relationship with the sex of the fetus. Whether it is a boy or a girl, under normal circumstances both kidneys are visible, not that both kidneys are visible is a girl. It is not possible to determine the sex of the fetus without medical indications in clinical practice.