What is anovulation?
Anovulation is a treatable condition of female infertility where a woman's ovaries fail to release an egg during a menstrual cycle, making it very difficult to become pregnant without medical assistance. Polycystic ovary syndrome (PCOS) is a leading cause of anovulation, but women can experience anovulation without PCOS.
Symptoms of anovulation
Chronic anovulation is one of the most common causes of female infertility, accounting for as many as 30% of cases. It causes menstrual cycle irregularities, such as extended or shortened cycles, or no menstrual cycle at all. Ovulation (the release of an egg from an ovary) typically occurs about halfway through a menstrual cycle. If you are unable to ovulate, you cannot become pregnant (unless you have frozen eggs or use an egg donor).
Becoming aware of the signs of ovulation (and monitoring your menstrual and ovulation cycles accordingly) can alert you to symptoms of ovulation dysfunction, which include:
- Irregular menstruation
- Excessive or light menstruation
- Lack of menstruation
- Lack of cervical mucus
- Irregular basal body temperature (BBT)
Experiencing menstruation does not necessarily mean a woman is ovulating normally.
Causes of anovulation
Polycystic ovarian syndrome (PCOS) is the most common cause of anovulation. Other potential causes of ovulation dysfunction include:
- Being overweight or underweight
- Exercising to an extreme degree
- Low ovarian reserves
- Thyroid dysfunction
- High stress levels
- Premature ovarian failure
Diagnosing anovulation in women
Your fertility doctor can diagnose anovulation by:
- Reviewing your medical history to determine if you menstruate on a normal cycle.
- Consulting blood test results to monitor levels of progesterone in the second half of a cycle. This is when the hormone surges to levels of 5 to 20 ng/ml.
- Performing a postcoital test, which involves taking a sample of cervical mucus soon after intercourse.
- Performing ultrasonography, typically intravaginal, to have a clear image of the reproductive tract and detect potential abnormalities. This tool is also used to monitor follicular development before ovulation.
- Conducting an endometrial biopsy to get a tissue sample taken from the endometrium (uterine lining). By studying the thickness and qualities of this tissue, it can be determined if ovulation has occurred and if the endometrium is healthy enough to support egg implantation and fetal growth.
Fertility treatment for anovulation
Because many factors influence a woman’s hormones and menstrual cycle, there is no single solution for treating anovulation. Often, the underlying cause of anovulation is addressed as part of the treatment. For example, lifestyle changes, such as weight loss or stress management, may be advocated by your physician.
In many cases, fertility drugs are prescribed to balance hormone cycles and trigger ovulation. The first recommendation is usually clomid, which initiates ovulation in up to 80 percent of women with anovulation.