All About Ovulatory Dysfunction and Anovulation

Symptoms, Causes, and Treatments for Anovulation

Empty egg shells, a metaphor for anovulation
Not ovulating? Anovulation is a common cause of infertility, with many treatment options. Photo: Shana Novak / Photodisc / Getty Images

What Is Anovulation?

Anovulation means lack of ovulation, or absent ovulation. Ovulation is the release of an egg from the ovary. This must happen in order to achieve pregnancy naturally. If ovulation is irregular, but not completely absent, this is called oligoovulation.

Both anovulation and oligovulation are kinds of ovulatory dysfunction.

Ovulatory dysfunction is a common cause of female infertility, occurring in up to 40% of infertile women.

What Are the Symptoms of Anovulation or Ovulatory Dysfunction?

Usually, women with anovulation will have irregular periods. In the worst case, they may not get their cycles at all.

If your cycles are shorter than 21 days, or longer than 36 days, you may have ovulatory dysfunction.

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 may also be a sign of ovulatory dysfunction.

For example, if one month your period is 22 days, the next it's 35, that much variation between cycles could signal an ovulation problem.

It is possible to get your cycles on an almost normal schedule and not ovulate, though this isn't common.

A menstrual cycle where ovulation doesn't occur is called an anovulatory cycle.

How Does Anovulation and Ovulatory Dysfunction Cause Infertility?

For a couple without infertility, the chances of conception are about 25% each month.

Even when ovulation happens normally, a couple isn't guaranteed to conceive.

When a woman is anovulatory, she can't get pregnant because there is no egg to be fertilized.

If a woman has irregular ovulation, she has fewer chances to conceive, since she ovulates less frequently.

Plus, late ovulation doesn't produce the best quality eggs.

This may also make fertilization less likely.

Also, irregular ovulation means the hormones in the woman's body aren't quite right.

These hormonal irregularities can sometimes lead to other issues, like...

What Causes Anovulation?

Anovulation and ovulatory dysfunction can be caused by a number of factors.

The most common cause of ovulatory dysfunction is polycystic ovarian syndrome, or PCOS. 

Other potential causes of irregular or absent ovulation:

How Is Anovulation Diagnosed?

Your doctor will ask you about your menstrual cycles. If you report irregular or absent cycles, ovulatory dysfunction will be suspected.

You doctor might also ask you to track your basal body temperature at home for a few months.

Next, your doctor will order blood work to check hormone levels.

One of those tests might include 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 may also order a ultrasound. The ultrasound will check out the shape and size of uterus and ovaries, and also look to see if your ovaries are polycystic, a symptom of PCOS.

Ultrasound can also be used to track follicle development and ovulation, though this isn't commonly done. In this case, you might have several ultrasounds over a one- to two-week period.

What Are the Potential Treatments for Anovulation?

Treatment will depend on the cause of the anovulation.

Some cases of anovulation can be treated by lifestyle change or diet. If low body weight or extreme exercise is the cause of anovulation, gaining weight or lessening your exercise routine may be enough to restart ovulation.

The same goes for obesity. If you are overweight, losing even 10% of your current weight may be enough to restart ovulation.

The most common treatment for anovulation is fertility drugs.

Usually, Clomid is the first fertility drug tried. Clomid can trigger ovulation in 80% of anovulatory women, and help about 45% get pregnant within six months of treatment.

If Clomid doesn't work, there are other fertility treatments left to try.

For women with PCOS, insulin sensitizing drugs like metformin may help a woman start ovulating again. Six months of treatment is required before you'll know if the metformin will work.

If metformin alone doesn't help, using fertility drugs in combination has been shown to increase the chance of success in women who didn't ovulate on fertility drugs alone.

The cancer drug letrozole (Femara) may be more successful at triggering ovulation in women with PCOS.

If the cause of anovulation is premature ovarian failure, or low ovarian reserves, then fertility drugs are less likely to work. But that doesn't mean you can't get pregnant with your own eggs.

Some women will be unable to conceive with their own eggs and may require IVF treatment with an egg donor.

Sources:

Infertility. National Library of Medicine: MedlinePlus.

Medications for Inducing Ovulation: A Guide for Patients. American Society of Reproductive Medicine.

Patient Fact Sheet: PCOS. American Society of Reproductive Medicine.

Continue Reading