Anovulation and Ovulatory Dysfunction

Ovulation is the release of an egg from the ovary. It must occur for pregnancy to be achieved naturally. Anovulation means a lack of ovulation or absent ovulation. When ovulation is irregular—but not completely absent—it is called oligo-ovulation.

Both anovulation and oligo-ovulation are types of ovulatory dysfunction. Ovulatory dysfunction is a common cause of female infertility. Up to 40% of infertile people with ovaries experience dysfunctional ovulation.

Anovulation and Infertility

When a couple is not experiencing infertility, the chances of conception are about 25% each month. However, even when ovulation happens normally, a couple is not guaranteed to conceive.

When a person is anovulatory, they cannot get pregnant because there is no egg to be fertilized. If a person has irregular ovulation, they will have fewer chances to conceive because they ovulate less frequently.

Late ovulation does not produce the best quality eggs, which can also make fertilization less likely. Additionally, irregular ovulation usually indicates there is something off about a person's hormone levels.

Hormonal irregularities can lead to other health issues, including:

• Abnormally low levels of progesterone
• Lack of fertile cervical mucus
• Shorter luteal phase
• Thinning or over-thickening of the endometrium (the lining of the uterus where a fertilized egg needs to implant)

Symptoms

People with anovulation usually have irregular periods. Some do not get their cycles at all.

If your cycles fall within the normal range of 21 to 36 days, but the length of your cycles varies widely from month to month, that could also be a sign of ovulatory dysfunction. For example, if one month your period is 22 days and the next it's 35, the variations between cycles could signal an ovulation problem.

While it is possible to get your menstrual cycle on an almost normal schedule and still not ovulate, it isn't common. A menstrual cycle where ovulation does not occur is called an anovulatory cycle.

Causes

Anovulation and ovulatory dysfunction can have several causes. The most common cause of ovulatory dysfunction is polycystic ovarian syndrome (PCOS).

Other potential causes of irregular or absent ovulation include:

• Extreme exercise
• Extremely high stress levels
• Hyperprolactinemia
• Low body weight
• Obesity
• Perimenopause or low ovarian reserves
• Premature ovarian failure
• Thyroid dysfunction (hyperthyroidism)

Diagnosis

Your doctor will ask you about your menstrual cycles at your annual wellness visit. If you report irregular or absent cycles, your doctor will want to determine if you have ovulatory dysfunction.

To start, you might be asked to track your basal body temperature at home for a few months. Next, your doctor will order blood tests to check your hormone levels.

One test might be a day 21 progesterone blood test. After ovulation, progesterone levels rise. If your progesterone levels do not rise, you are probably not ovulating.

Your doctor might also want to perform an ultrasound. This will let them see the shape and size of the uterus and ovaries. They can also see if your ovaries are polycystic (a symptom of PCOS).

Ultrasound can also be used to track follicle development and ovulation, though it is not commonly done. If your doctor decides to go this route, you might need to have several ultrasounds done over a one- to two-week period.

Treatment

The treatment for anovulation will depend on what is causing it. Some cases can be treated with changes to your lifestyle or diet. For example, if your low body weight or extreme exercise habit is the cause of anovulation, gaining weight or easing up on your workout routine might be enough to restart ovulation.

The same is true when anovulation is caused by obesity. If you are overweight, losing even 10% of your current weight might be enough to restart ovulation.

The most common treatment for anovulation is fertility drugs. Clomid is the first fertility drug that is usually tried. If Clomid does not work, your doctor might want to try other fertility treatments.

If you have PCOS, insulin-sensitizing drugs like metformin might help you start ovulating again. However, six months of treatment is required before you'll know if the metformin will work. Afterward, try taking a pregnancy test.

If taking metformin alone doesn't help, your doctor might recommend taking fertility drugs combined with metformin. The combination has been shown to increase the chance of success in women who did not ovulate using fertility drugs alone.

For people who have PCOS, the cancer drug letrozole (Femara) might be more successful at triggering ovulation.

Fertility drugs are less likely to work when the cause anovulation is premature ovarian failure or low ovarian reserves. That doesn't mean you can't get pregnant with your own eggs, but some people will be unable to conceive using their own eggs and will need IVF treatment with an egg donor.