Pregnant women tend to form corpus luteum cysts. The diameter of the corpus luteum during normal and pregnancy is less than 2 cm. If the diameter of the corpus luteum reaches 2 to 3 cm, it is called a cystic corpus luteum; if the diameter is greater than 3 cm, it is called a corpus luteum cyst. When the cystic corpus luteum or corpus luteum cyst degenerates, it turns into hyaline connective tissue, but still retains the cystic cavity and the fluid in the cystic cavity. Its diameter is 2 to 3 cm, which is called a cystic white body. The diameter is greater than 3 cm, which is called a white body cyst. Ovarian corpus luteum cysts may cause cyst rupture and bleeding due to some reasons, and in severe cases, it may cause acute abdomen.