Anovulation overview

  • Anovulation is a common condition in which a woman does not ovulate, meaning her ovaries do not release an egg.
  • Anovulation is most frequently caused by a hormonal imbalance and may also be caused by problems in the ovaries and follicles.
  • The absence or irregularity of periods are common symptoms of anovulation.
  • Many treatments for anovulation are fairly simple, such as correcting a hormonal imbalance to help the ovaries produce eggs on a regular basis.

What is anovulation?

Anovulation occurs when a woman’s ovaries do not develop or release eggs. This common condition accounts for approximately 30 percent of all infertility cases in women. Typically, women ovulate every 24-34 days, from menarche (the first period) to menopause. If a woman only has her period every few months, or not at all (amenorrhea), she may be ovulating irregularly or not at all.

What causes anovulation?


Anovulation typically occurs when a woman’s hormones are off balance. During a woman’s menstrual cycle the luteinizing hormone (LH), follicle-stimulating hormone (FSH), estrogen and progesterone work together to cause ovulation. If even one of these hormone’s levels is wrong, then ovulation may not be possible.

These four hormones are among the first things a reproductive specialist will check. Hormonal issues include:

  • Failure to produce mature eggs, due to abnormal ovarian follicles in which the eggs mature. This occurs in 50 percent of anovulation cases and is most often caused by polycystic ovary syndrome (PCOS).
  • Improper function of the hypothalamus section of the brain, which can result in failure to signal hormone production necessary for eggs to mature.
  • Pituitary gland malfunction that can cause an imbalance of FSH and LH, resulting in improper ovulation. This can be caused by over exercising or being underweight.
  • Obesity can cause a woman’s body to produce excessive androgens, insulin and testosterone, which can have a negative effect on the menstrual cycle, making it irregular or non-existent.
  • Stress induced anovulation (SIA) affects about 5 percent of reproductive age women. High stress levels affect the hypothalamus’ release of gonadotropin-releasing hormone (GnRH) and the pituitary gland’s release of LH and FSH.

Scarred ovaries

Ovaries that are damaged, which can occur from infection or repeated surgeries to remove ovarian cysts, may become scarred and inhibit follicle maturation so ovulation doesn’t happen.

Unruptured follicle syndrome

A woman may produce a normal follicle with an egg inside it but the follicle fails to release the egg from the ovary.

Premature ovarian failure, also called premature menopause, and low ovarian reserve can also cause anovulation. These conditions are generally not reversible.

What are the symptoms of anovulation?

Skipping periods or the absence of periods altogether are common symptoms of anovulation. Physical symptoms that can contribute to anovulation include being obese, being underweight or having extreme emotional stress.

Treatment for anovulation

If a woman is experiencing anovulation, she should seek medical council to determine the cause. A doctor will typically do a physical exam, blood work and studies of ovarian reserve and ovulation. Once anovulation is properly diagnosed, medications can be prescribed for ovulation induction or hormone therapy.

If ovulation inducing medications or hormone therapy are unsuccessful in restoring normal ovulation, a woman may be recommended to proceed with in vitro fertilization (IVF). IVF involves a reproductive specialist removing a woman’s eggs directly from her ovaries, eliminating the need for ovulation altogether. The egg will be fertilized by her partner’s sperm in an IVF lab and the resulting embryo(s) will be implanted directly into her uterus.