The causes of sail-shaped placenta may be related to placenta hypoplasia or intrauterine congestion, which need to be analyzed specifically. 1. Placenta hypoplasia: it may be related to the placenta hypoplasia in early pregnancy. As the pregnancy progresses, the placenta grows towards the upper part of the uterus where the blood supply is more abundant, which leads to the umbilical cord attaching to the umbilical cord deviating from the center position, thus triggering the emergence of sail-shaped placenta. 2. Intrauterine congestion: It may be related to intrauterine congestion induced by various reasons, including infection of the uterine cavity, fetal malformation, intrauterine mechanical factors, and multiple pregnancies, etc., all of which may trigger the appearance of sail-shaped placenta. In addition, the greater the number of intrauterine pregnancies with a fetus, the greater the chance of sail-like placenta. In addition, sail-like placenta can be harmful, and it is recommended that pregnant women have the need to receive active treatment under the guidance of a specialist.