A follicle that grows and doesn’t break may form a cyst and may cause a woman to become infertile. Normally, a follicle is considered mature when it grows to 18 millimeters or more and may ovulate at any time. However, some women do not ovulate when their follicles are mature, which may result in the formation of luteinized cysts and may also cause infertility. 1. There is cyst formation. When a follicle matures and does not ovulate, it can become luteinized and form a luteinized cyst. If this cyst is small, it basically has no effect. However, if the cyst is large, it may twist or rupture, resulting in severe abdominal pain and even hemorrhagic shock. 2. Infertility. After the follicle is ovulated, the egg may combine with the sperm to form a fertilized egg. If the follicle does not ovulate after maturation, the sperm will not be able to combine with the egg, so it will cause female infertility.