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.
According to the National Institute of Health, Anovulation accounts for nearly 30% of female factor infertility. Women experiencing anovulation may also experience an irregular or lack of menstruation. However, anovulatory cycles may also incur bleeding, which many women mistake for normal menstruation.
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 due to an imbalance of hormones that cause a woman to ovulate. Other potential causes of ovulation dysfunction include:
- Obesity: Women with a high BMI may experience a chemical imbalance due to an excess of androgens (like testosterone).
- Polycystic Ovary Syndrome (PCOS): PCOS impacts nearly 1 in 10 women of childbearing age in the U.S. alone, and is a leading cause of anovulation. PCOS causes a woman's body to make an excess of androgens (male hormones), and can make the ovaries' follicles containing eggs remain small.
- Low body weight and extreme exercise: A low BMI or regular, intense physical exercise can hurt the pituitary gland and decrease the LH and FSH needed to ovulate regularly.
- Thyroid dysfunction: Thyroid-stimulating hormone and prolactin are two hormones released by the brain. Imbalances in TSH or Prolactin can interfere with ovulation and lead to anovulation in women around childbearing age.
- High stress levels: Excessive stress and anxiety can lead to GnRH, LH and FSH becoming imbalanced.
Diagnosing anovulation in women
The most significant part of anovulation is the absence of menstraution cycles. Still, your fertility doctor can perform other tests to anovulation by:
- Reviewing your medical history to determine if you menstruate on a normal cycle.
- Consulting blood test results to monitor levels of progesterone, thyroid and prolactin levels 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, decreasing exercise habits, 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.
IVF and IUI
In some cases, women experiencing anovulation that wish to become pregnant may be recommended In Vitro Fertilization or Intrauterine Insemination. To learn more about IVF and IUI with the presence of anovulation, we encourage you to reach out and speak with our fertility specialists.