What Is Anovolation?

A Common Cause of Infertility

Ovulation is when an egg is released from the ovary and positions itself for fertilization. Anovulation is a condition in which a person does not ovulate. The condition is a common cause of infertility.

Anovulation can occur secondary to various underlying causes, including hormone imbalances, being overweight or underweight, and other medical conditions affecting the reproductive system.

Treatment for anovulation varies depending on the cause but may include lifestyle changes, medication, and in vitro fertilization (IVF) for people who want to get pregnant. 

A digital illustration in blue of an ovary and fallopian tube on a black background.

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How Ovulation Works

Ovulation occurs when the brain releases a hormone called gonadotropin-releasing hormone (GnRH). The hormone subsequently causes the pituitary gland to release two more hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

FSH stimulates the ovary's follicles (which contain the eggs) that make the hormone estrogen. This hormone is instrumental in building the uterine lining in preparation for receiving a fertilized egg.

Next, LH is released (called an LH surge), which in turn causes the release of the egg from the ovary. The egg moves into the fallopian tube, where fertilization can occur if sperm is present. 

Once the egg is released into the fallopian tube, fertilization must take place within 12 to 24 hours. After that time, the egg is no longer viable. 

If the egg is not fertilized, levels of another hormone called progesterone decrease, causing the lining of the uterus to shed because it is not needed. This bleeding is called menstruation (or a person's period).

What Is Anovulation?

Anovulation is a condition of the reproductive system in which the ovaries do not release an egg during the menstrual cycle. Since no egg is released, fertilization cannot occur. Long-term (chronic) anovulation can cause infertility. 

Anovulation is often linked with irregular menstrual cycles but not always. Bleeding sometimes occurs during anovulatory cycles and can be mistaken for menstruation. However, when bleeding occurs during anovulatory cycles, it rarely occurs regularly. 

Causes of Anovulation

Ovulation is a complex process involving glands, organs, hormones, and other chemicals that must be released in a specific sequence for ovulation to occur.

There are several underlying causes of anovulation, including:

  • Abnormalities in hormone levels: There is a very complex sequence of hormonal interactions that must happen for ovulation to occur. Abnormal levels of hormones such as thyroid-stimulating hormone (TSH) and prolactin can disrupt normal ovulation.  
  • Polycystic ovary syndrome (PCOS): A disorder involving cysts on the ovaries that occurs commonly in those who are of childbearing age. PCOS is a common cause of anovulation because it creates an imbalance of the hormonal sequence necessary for ovulation. Instead of the release of the normal level of estrogen and progesterone, PCOS causes an increase in androgens called testosterone. High levels of testosterone cause the follicles in the ovaries (which contain the egg) to remain small.
  • Age-related: When a person initially starts to menstruate, anovulation is common. It also occurs in those approaching menopause (a period called perimenopause). The cycles of anovulation that occur during these transitional periods are caused by an imbalance of hormones. 
  • Weight-related: A 2016 study of 376 infertile women with ovulatory dysfunction found that being at an excessively low weight or being overweight increased a person's risk of infertility. Obesity interrupts the normal release of gonadotropin-releasing hormone (GnRH) produced by the hypothalamus, follicle-stimulating hormone (FSH), and luteinizing hormone (LH), thus causing irregular or anovulatory cycles. Low body weight or too much physical exercise can negatively impact the pituitary gland function, resulting in low levels of FSH and LH.
  • Stress: Consistently high levels of stress and anxiety can also result in an imbalance of GnRH, LH, and FSH hormones, which can lead to ovulation issues and missed periods.
  • Medications: Some medications, such as certain antipsychotics, can disrupt the menstrual cycle and may affect ovulation. Other medications, like hormonal birth control pills, are designed to inhibit or prevent ovulation.
  • Genetic defects: Several single-gene mutations are thought to be associated with anovulation, particularly in people with polycystic ovaries.

Anovulation Symptoms

People who ovulate may have several signs that typically occur during each cycle, including:

  • Regular periods (menstruation)
  • An increase in cervical mucus
  • A drop in resting body temperature around day 10 to 16 of the monthly menstrual cycle

The absence of these signs of regular ovulation may indicate that a person is not ovulating.

Diagnosing Anovulation

The absence of regular menstruation is the most apparent sign of anovulation. Some tests can be done to make a formal diagnosis, including:

  • An ultrasound exam of the ovaries, uterus, and other pelvic organs
  • A luteinizing hormone level test
  • A progesterone level test
  • Other tests (such as blood tests or testing the lining of the uterus)

Anovulation Treatment

There are several treatments for anovulation, but the type of treatment will depend on what is causing a person to have anovulatory cycles.

Lifestyle Changes

In some cases, lifestyle changes like following a nutritious diet and exercising might be recommended, especially if a person's weight might be contributing to their anovulation.

For example, a person with obesity might be able to address ovulatory dysfunction by losing weight. On the other hand, if a person is underweight and not ovulating, nutritional counseling might help them gain weight.

Physical activity can be useful for people who are trying to lose weight in a sustainable, safe way, but it can also contribute to period problems when it is done in excess. People who need to gain weight rather than lose it to restore their period and ovulation cycles might need to adjust how much they are exercising, or choose different types of exercise.

Stress can also affect a normal menstrual cycle by interfering with pituitary hormones. Finding ways to reduce stress can benefit a person's overall health and may help their body begin to ovulate again.

Medical Intervention

Some people who are not ovulating might benefit from trying different types of medication, depending on the reason they have stopped ovulating normally.

Medications that a doctor might prescribe for a person with anovulation include:

Summary

Anovulation is a condition of the reproductive system. During a normal menstrual cycle, an ovary releases an egg. During an anovulatory cycle, no egg is released and therefore fertilization cannot occur.

There are many underlying causes of anovulation, and the treatment approaches will depend on why ovulation is not occurring. For example, if a person is underweight, they might need to restore their nutrition and gain weight to begin ovulating again.

If they have a condition like polycystic ovary syndrome, which is linked to anovulation and infertility, treating that condition will be necessary to help ovulation resume.

A Word From Verywell

If you have noticed any changes in your menstrual cycle, it's important to talk to your doctor. If you are not ovulating, your doctor can ask you about your health and run tests to figure out why.

They might also refer you to a doctor who specializes in treating hormonal issues (endocrinologist) who can do a more thorough evaluation and recommend treatment.

Frequently Asked Questions

What causes anovulation?

There are several possible underlying causes of anovulation, including hormonal problems, obesity, excessive exercising, being underweight, chronic stress, and more.

How common is anovulation?

Researchers are not sure how many people experience anovulation, but studies have suggested that it occurs in anywhere from 3% to 23% of people with ovaries who are in their reproductive years.

How can you tell ovulation from anovulation?

Some people notice specific signs or symptoms around the time in their cycle that they ovulate. Using an over-the-counter (OTC) ovulation predictor test can also help a person figure out if they are ovulating.

Another way of detecting ovulation is by monitoring resting body temperature; a drop and subsequent rise in resting body temperature around day 10 to 16 of the menstrual cycle may indicate that ovulation has occurred.

How does binge eating cause anovulation?

A 2014 study reported that “binge eating is associated with menstrual dysfunction," and that "metabolic and endocrinological factors could underlie this association.”

How do you overcome anovulation naturally?

Natural methods of addressing anovulation, like medical methods, will depend on what is causing it. Losing or gaining weight, eating a nutritious diet, making sure that you are not exercising too much, and managing stress are a few ways that you might be able to help your body start ovulating again.

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9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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