Irregular or abnormal ovulation accounts for approximately 25 percent of all infertility cases. Ovulation normally occurs 12 to 16 days before the onset of menstruation. During ovulation, progesterone is released. Progesterone is the hormone that transforms the uterine lining into a receptive environment for implantation and nurturing of the fertilized egg.

There are several tests to determine the regularity of ovulation. A woman may complete a basal body temperature chart by taking and recording her temperature orally each morning for a month. The release of progesterone usually causes a 0.5 to 1 degree rise in temperature. She may also use an over-the-counter prediction kit that tests the urine.

A physician may perform a pelvic ultrasound examination or a biopsy to evaluate ovulation. If a woman is not ovulating, she may be prescribed medication to stimulate ovulation. Up to 80 percent of women taking ovulation drugs begin to ovulate regularly. If no other factors need treatment, more than 50 percent may become pregnant within the first six induced ovulations.