Anovulation

Anovulation is a common cause of infertility. It means you’re not ovulating or releasing an egg. Hormonal imbalances typically cause it, and the main symptom is having irregular vaginal bleeding. Healthcare providers treat anovulation with lifestyle changes and/or medication to help balance your hormones.

Overview

What is anovulation?

Anovulation (also called an anovulatory cycle) happens when an egg doesn’t release from your ovary (ovulation). Ovulation only happens one time during your menstrual cycle. The egg that your ovary releases at ovulation has the potential to be fertilized by sperm and create a pregnancy.

Anovulation often happens due to a hormone imbalance. Since multiple hormones contribute to ovulation, there can be many causes of anovulation. Because ovulation is critical to pregnancy, anovulation is a common cause of infertility.

Being aware of your menstrual cycle length and understanding how your body changes throughout your cycle can help you identify signs of anovulation. It’s important to contact a healthcare provider if you notice irregular menstrual cycles or abnormal vaginal bleeding so they can determine an underlying cause and recommend treatment.

How does ovulation work?

Ovulation typically happens on day 14 of a 28-day menstrual cycle. The exact day can vary and, depending on the length of your menstrual cycle, happen sooner or later.

The process of ovulation begins when your hypothalamus (a part of your brain) releases gonadotropin-releasing hormone (GnRH). GnRH causes your pituitary gland (a gland in your brain) to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

Between days six and 14 of your menstrual cycle, FSH causes follicles (small sacs of fluid in your ovaries that contain a developing egg) in one ovary to begin to mature. During days 10 to 14 of the cycle, only one of the developing follicles forms a fully mature egg. Around day 14 in the menstrual cycle, a sudden surge in LH causes the ovary to release its egg.

You can think of ovulation as an orchestra with your hormones acting as the instruments. When everything is playing in harmony, the song can flow from beginning to end effortlessly. But, if even one instrument is off-key, it messes up the entire song. The other hormones are completely thrown off and can’t do their part of the song. This is similar to what happens if one hormone is slightly off in the days leading up to ovulation.

Who does anovulation affect?

Anovulation can affect anyone who has ovaries and is of child-bearing age, which, on average, is between the ages of 12 and 51. If any of the following conditions or situations apply to you, you’re more likely to experience anovulation:

How common is anovulation?

Anovulation is a common condition and is the cause of approximately 30% of infertility cases.

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Symptoms and Causes

What are the signs and symptoms of anovulation?

Being aware of the general signs of ovulation and keeping track of your menstrual cycles can help alert you to signs and symptoms of anovulation. It’s important to remember that having a period doesn’t necessarily mean you’ve ovulated. Signs and symptoms of anovulation can include:

  • Having irregular periods: If the length of time in between your periods keeps changing, it’s an irregular period. The average menstrual cycle is 28 days, but it can be a couple of days shorter or longer than that.
  • Having very heavy or light periods: A heavy period is losing over 16 teaspoons (80 mL) of blood within your period and/or having a period that lasts longer than seven days. Blood loss of fewer than 4 teaspoons (20 mL) throughout your period is considered a light period. It may be easier to note how often you fill a sanitary pad during your period. In general, filling a pad every hour for several hours in a row indicates a heavy period.
  • Not getting periods (amenorrhea): Missing one or more periods without being pregnant could be a sign of anovulation.
  • Not having egg white cervical mucus: Right before and during ovulation, your vaginal discharge should resemble raw egg whites. It becomes clear, slippery and stretchy. If you don't have this discharge, you may be experiencing anovulation.
  • Having an irregular basal body temperature: Your basal body temperature is your temperature when you’re fully at rest. You can take it right after you wake up and before you get out of bed. Ovulation can cause a slight increase in your basal body temperature.

Can you have anovulation and still have your period?

Menstruation, or getting your period, happens because an egg wasn’t fertilized by sperm. When you don’t ovulate, there’s no egg to fertilize. Because of this medical definition, you technically can’t menstruate without ovulating.

However, you can still bleed — experience a “period” — without ovulating. This is known as abnormal uterine bleeding (AUB), or anovulatory bleeding. AUB is uterine bleeding that’s irregular and doesn’t follow a cycle. Abnormal uterine bleeding is common — approximately 30% of people assigned female at birth (AFAB) experience it at some point in their lives.

What causes anovulation?

In general, the cause of anovulation is an imbalance of one or more hormones, especially the hormones involved in ovulation, which include:

  • Gonadotropin-releasing hormone (GnRH).
  • Follicle-stimulating hormone (FSH).
  • Luteinizing hormone (LH).

However, even hormones that aren’t directly involved in ovulation, such as testosterone and prolactin, can impact the hormones your body needs for ovulation. The following hormone imbalances and conditions can cause anovulation:

  • High androgen levels.
  • Pituitary gland dysfunction.
  • High prolactin levels.
  • Underactive thyroid.
  • Low gonadotropin-releasing hormone (GnRH) levels.

High levels of androgens (hyperandrogenism)

Androgens are a group of hormones that help with growth and reproduction. Typically, androgens are thought of as male-specific hormones, but the female body produces a small amount of androgen hormones, too. Androgens include testosterone, androsterone and androstenedione. Your gonads (ovaries or testicles) and your adrenal gland produce androgens.

When a person with ovaries has a higher-than-normal level of androgen hormones in their blood, it’s called hyperandrogenism. The follicles in your ovaries contain eggs. A high level of androgens can cause these follicles to stay small instead of enlarging and maturing like they’re supposed to before ovulation. Conditions that can cause hyperandrogenism include:

Pituitary gland dysfunction (hypogonadotropic hypogonadism)

Your pituitary gland produces luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are needed for ovulation. If your pituitary gland isn’t releasing enough LH and FSH, it can cause anovulation. Conditions and situations that cause your pituitary gland not to release enough LH and FSH include:

High levels of prolactin (hyperprolactinemia)

Prolactin is a hormone that your pituitary gland releases mainly for stimulating breast milk production (lactation). But prolactin also suppresses luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are needed for ovulation. Because of this, a high amount of prolactin in your blood can cause anovulation. Conditions and situations that can cause hyperprolactinemia include:

  • Breastfeeding.
  • A type of pituitary gland tumor called a prolactinoma.
  • Damage to your pituitary gland.
  • Damage to or illness of your kidneys, liver and/or thyroid.
  • Certain medications, such as psychotropic drugs, narcotics and drugs that treat ulcers or elevated levels of stomach acid.

Low levels of thyroid hormones (hypothyroidism, or underactive thyroid)

Your thyroid — the butterfly-shaped gland in the front of your neck — produces two hormones that are needed for many important bodily functions: triiodothyronine (T3) and thyroxine (T4). Having a low level of thyroxine in your blood can increase the amount of prolactin your pituitary gland makes. Prolactin suppresses luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are necessary for ovulation, so a low level of thyroxine can cause anovulation. Conditions and situations that can cause hypothyroidism include:

Low levels of gonadotropin-releasing hormone (GnRH)

Your hypothalamus (a part of your brain) produces gonadotropin-releasing hormone (GnRH). GnRH triggers the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are needed for ovulation. Because of this, having low levels of GnRH in your blood can cause anovulation. Damage to your hypothalamus can cause low levels of GnRH.

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What are the risk factors for anovulation?

Risk factors for having anovulation can include:

  • Having polycystic ovary syndrome (PCOS): PCOS is a common condition that causes 70% of anovulation cases. PCOS causes your body to make too many androgens, which cause the follicles in your ovaries to remain small instead of maturing and growing as they should to prepare for ovulation.
  • Having obesity: Having obesity can cause your body to make too many androgens, which affects your ovaries’ ability to produce mature follicles.
  • Having a low body weight and/or doing long-term excessive exercise: A very low body mass index (BMI) or participating in routine intense physical exercise can affect your pituitary gland, which could cause it not to produce enough luteinizing hormone and/or follicle-stimulating hormone. These hormones are needed to ovulate regularly.
  • Experiencing excessive stress: Experiencing excessive stress can cause imbalances in your body’s gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are all needed for ovulation.
  • Having just started getting periods or having your last periods: During both of these transitional times, an imbalance in your body’s hormones can cause anovulation.

What are the complications of anovulation?

Anovulation can potentially cause complications. Not everyone will experience complications, though. Some possible complications include:

  • Infertility: Not ovulating can be a major cause of infertility.
  • Amenorrhea: This is the medical term for not getting a regular menstrual period.
  • Hormonal imbalances: Not ovulating or getting a period is one sign of hormonal imbalance, but there can be others. Other hormonal imbalance symptoms could include weight gain, hair loss and acne.

It can also increase your risk for the following health conditions:

  • Endometrial hyperplasia: When the lining of your uterus (endometrium) doesn’t shed properly due to the lack of progesterone, it can get too thick.
  • Osteoporosis: This is mainly due to not having enough estrogen, which is critical for maintaining strong bones.
  • Cardiovascular disease: Some studies show that hormone changes can increase your risk for conditions that also increase your risk for cardiovascular diseases. For example, low estrogen levels can contribute to increased insulin resistance, which increases your risk for diabetes.
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Diagnosis and Tests

How is anovulation diagnosed?

In general, the diagnosis of anovulation is having irregular periods. Your healthcare provider can determine if you have anovulation by listening to your symptoms and noting that you don’t menstruate regularly.

However, your healthcare provider will want to investigate and determine the cause of your anovulation, which may lead to another diagnosis.

What tests will be done to diagnose anovulation?

Tests for diagnosing anovulation depend on what your healthcare provider suspects are causing anovulation. It’ll mainly consist of hormone blood tests. Tests that can help diagnose anovulation include:

  • Blood progesterone levels.
  • Blood thyroid levels.
  • Blood prolactin levels.
  • An ultrasound exam of your pelvic organs.

Many of the hormone imbalances that cause anovulation have other symptoms, so your provider may have you undergo other tests if you’re experiencing symptoms of a certain hormone imbalance condition.

Management and Treatment

What is the treatment for anovulation?

Treatment for anovulation depends on correcting the hormonal imbalance that’s causing it, if possible.

In general, lifestyle changes that may treat your anovulation include:

  • Managing your stress: If your healthcare provider suspects that stress could be causing anovulation, they’ll likely recommend trying to limit your stressors and using techniques such as meditation, yoga or deep breathing to better cope with stress.
  • Maintaining a weight that’s healthy for you: If you have obesity, your healthcare provider may recommend trying to lose weight to treat your anovulation. If you have a low body mass index (BMI), your healthcare provider may recommend gaining weight to treat your anovulation. If either of these situations applies to you, be sure to talk to your provider and/or a registered dietitian to manage your weight safely and in a way that works for you.
  • Decreasing your exercise frequency and intensity: If your healthcare provider suspects that your exercise routine and intensity are causing your anovulation, they may recommend limiting the amount of time you exercise and the intensity of the exercises.

Other treatments for anovulation include:

  • Certain medications to treat other conditions: If you have a treatable condition that’s causing your anovulation, your healthcare will likely prescribe you medication, which could also treat your anovulation. For example, if you have hypothyroidism, which can cause anovulation, taking medication to treat your hypothyroidism could also treat your anovulation.
  • Adjusting current medications: Some medications can cause anovulation, such as anti-epileptic drugs and antipsychotic drugs. If you’re trying to conceive, your healthcare provider might adjust your current medications to try to treat your anovulation, if possible. Never adjust or stop taking your medications without seeing your healthcare provider. Always follow the instructions on your prescribed medications.
  • Clomiphene citrate (CC): This is often the first line of treatment for anovulation. It has about an 80% success rate in helping you ovulate. A common brand name is Clomid®.
  • Letrozole: Although it’s an off-label use (meaning that it’s not FDA-approved to treat anovulation but research indicates that it could help treat this condition), some healthcare providers recommend this type of medication to induce ovulation instead of clomiphene citrate. The brand name for this medication is Femara®.
  • Human chorionic gonadotropin (HCG) injection: This hormone causes your ovary to release an egg. Your provider can give you a synthetic form of it through an injection. It’s often taken with clomiphene citrate or letrozole.
  • Follicle-stimulating hormone (FSH) injection: If your body isn’t making enough FSH and other treatments for anovulation haven’t worked, your healthcare provider may have you get an injection of synthetic FSH to help your ovary release an egg.
  • Gonadotropin-releasing hormone (GnRH) agonist and antagonist injections: An injection of GnRH agonists and antagonists helps to control the levels of luteinizing hormone (LH) your body makes, which is needed for ovulation.

If fertility and pregnancy are your goal, and lifestyle changes and/or medication don’t help to treat your anovulation, there are still ways you may be able to experience pregnancy. Talk to your healthcare provider or a fertility specialist about in vitro fertilization (IVF) or intrauterine insemination (IUI).

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Prevention

Can I prevent anovulation?

You can’t prevent anovulation, but some of the reasons you have anovulatory cycles can be due to things you can manage. Things you can help manage include:

  • Healthy habits: Getting enough sleep, eating nutritious foods, exercising moderately and managing stress levels can all help you regulate hormones and contribute to overall hormonal health.
  • Tracking your cycles: Keeping records of your cycle length and symptoms can help you identify irregularities. Note things like when you bleed and how much or if you notice a chance in your vaginal discharge. It’s also helpful to have this data for your healthcare provider.
  • Treating hormonal imbalances: Treating conditions like PCOS or thyroid dysfunction with medication or other treatments can increase your chances of ovulation.

Outlook / Prognosis

What is the prognosis (outlook) for anovulation?

The outlook for anovulation depends on the cause of your anovulation. In most cases, lifestyle changes, fertility drugs or medication that treats the underlying health condition can treat anovulation. If you’re experiencing perimenopause, anovulation is more difficult to treat because hormonal changes are a natural and normal part of reaching menopause. Your healthcare provider can still help treat your symptoms, though.

How long does anovulation last?

Depending on the cause, anovulation can be temporary or chronic. It varies depending on your situation. Medication and/or lifestyle changes can often — but not always — treat anovulation.

Can I get pregnant if I have anovulation?

Lifestyle changes and/or medication can often treat anovulation, which means you’ll have an opportunity to get pregnant. But there are many other factors that contribute to a successful pregnancy.

If you’re receiving treatment for anovulation and are still having a difficult time getting pregnant, your provider may recommend in vitro fertilization (IVF) or intrauterine insemination (IUI).

Living With

When should I see my healthcare provider?

Contact your healthcare provider if any of the following apply to you:

  • You have vaginal bleeding at unpredictable and random intervals.
  • When you do bleed, it’s very heavy or very light, or lasts longer than one week.
  • You have pelvic or abdominal pain.
  • You haven’t been able to conceive after six months (if you’re older than 35) or one year (if you’re younger than 35) of having regular, unprotected sex.

If you’re receiving treatment for anovulation and still having issues conceiving, contact your healthcare provider or fertility specialist.

What questions should I ask my doctor?

If you’re experiencing anovulation, it may be helpful to ask your healthcare provider the following questions:

  • What’s causing my anovulation?
  • Do you recommend any lifestyle modifications to help with anovulation?
  • What medications could I take for my anovulation?
  • How long will it take to treat my anovulation?
  • How long should I try treatment for my anovulation before I consider IVF or IUI?
  • Can I still get pregnant?

A note from Cleveland Clinic

Experiencing anovulation can be a frustrating, disappointing and confusing time, especially if it’s contributing to infertility. While it’s natural to feel uncertain about your future or wonder if you’ll be able to conceive, try to put your trust in your healthcare provider. Even you’re not trying to get pregnant, you should still seek treatment because anovulation can contribute to health complications like osteoporosis or cardiovascular disease. Your healthcare provider can help you figure out the cause of your anovulation and suggest the right treatment for you. Remember, you’re not alone and there’s hope that your provider will get your menstrual cycles on track.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 02/14/2024.

Learn more about our editorial process.

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