Irregular ovulation or complete lack of ovulation (called oligo-ovulation and anovulation, respectively) are some of the most common causes of infertility. There are several reasons why the ovary may not work properly, and the best clue that you may not be ovulating is usually that the menstrual cycle falls outside the normal 27-32 day range.
Frequently the LH and FSH signals from the pituitary gland in the brain are not arriving at the ovary in the right way, resulting in irregular cycles and problems with fertility. This condition is commonly associated with increased body weight, excess hair growth or acne, and other findings consistent with the polycystic ovary syndrome (PCOS). This is such a common disorder that we have devoted an entire chapter to its discussion later in the book. PCOS is a highly treatable condition.
Women who are either too thin or exercise too much, or are too heavy can have a disruption of the signals between the brain and the ovaries that causes anovulation. In these cases, there is usually nothing wrong with the ovaries themselves, they are merely not getting the right signals from the brain. This condition is termed hypothalamic anovulation because it is the signals from the hypothalamus that are the problem. In other words, the car is fine, but the ignition switch is malfunctioning.
Less commonly, however, the problem resides within the ovary itself. In about 1 percent of women of childbearing age, the ovary runs out of eggs prematurely. In this case the ignition switch (the hypothalamus) and the gas pedal (the pituitary) are both working, but the engine itself (the ovaries) is broken. This can happen at any age, including the teens. This is known as premature ovarian failure, and it is probably the most difficult type of infertility to treat. This problem is diagnosed by testing FSH levels in the blood which will be elevated in cases where the egg supply is diminished or absent. Issues involving the quality of the eggs increase dramatically as women enter their mid-to-late thirties and early forties.
Other hormonal imbalances, such as with the thyroid or adrenal glands, can also cause ovulation problems. Such problems can usually be detected by simple blood tests, but only if you seek help to have the evaluation! If your cycles are irregular, you are probably not ovulating properly and should seek help right away.