What is Primary Ovarian Insufficiency (POI)?
Primary ovarian insufficiency (POI), previously known as premature ovarian failure (POF) or early menopause, is a condition in which the ovaries stop functioning normally before the age of 45.
It affects approximately 1% of women and occurs when the ovaries become depleted of eggs and stop functioning normally before the age of 40. When this happens, the woman’s estrogen level decreases drastically and her menstrual cycles become irregular or completely stop. Ovarian failure can cause bone loss (osteoporosis) and a variety of menopausal symptoms including hot flashes, vaginal dryness, night sweats, difficulty sleeping and irritability.
Understanding Primary Ovarian Insufficiency (POI) and the Life Cycle of the Human Ovary
To understand primary ovarian insufficiency (POI) and how ovaries become depleted of eggs, it’s important to understand the life cycle of the human ovary. By mid-gestation in fetal life, the human ovary possesses 7 million potential eggs. By the time a baby is born, about 85% of those eggs are lost, leaving most humans with an estimated 1 million eggs. No new eggs are produced after mid-gestation.
After birth, the number of eggs in the ovary continues to gradually decrease, so that by puberty only 200,000 eggs remain.
Throughout life, more eggs are lost through menstrual cycles. In a typical cycle, multiple eggs are recruited, but only one egg is released and the remaining eggs are lost.
In the span of a woman’s reproductive life, only 400 eggs are released (ovulations). The remaining ones are lost and never participate in the process of ovulation.
What causes POI?
The exact cause of primary ovarian insufficiency (POI) is often unknown, and in many cases, it is considered idiopathic, meaning there is no identifiable cause. However, research suggests that various factors can contribute to the development of POI:
- Medical treatments such as chemotherapy and radiation therapy
- Genetic causes such as:
- Turner’s syndrome in which a woman has only one normal X chromosome and an altered second X chromosome
- Fragile X syndrome
- Autoimmune disorders affecting the ovaries, thyroid or adrenal glands
- Ovarian surgery for benign diseases such as severe and recurrent endometriosis or recurrent ovarian cysts
- POI occurs more frequently when there is family history of primary ovarian insufficiency
- Cigarette smoke, chemicals, pesticides and viruses might hasten ovarian failure
In 50% of women affected by POI, the exact cause may be never known.
How is POI diagnosed?
Diagnosing primary ovarian insufficiency (POI) involves a comprehensive evaluation that typically includes the following:
- Careful review of the medical history
- Hormone testing for Follicle Stimulating Hormone (FSH), Estrogen and Antimullerian Hormone (AMH).
- Ultrasound to count the number of eggs remaining in the ovary (Antral follicle Count or AFC)
- Genetic testing including chromosomal analysis and Fragile X mutation.
Can POI be treated?
For women with primary ovarian insufficiency (POI) who want to conceive, there are no proven options to permanently restore ovarian function resulting in successful birth of a genetically related offspring. At present time only 10% of women with POI may conceive with their own eggs. In most cases of premature ovarian insufficiency, the only reliable strategy to achieve pregnancy is the use of donor eggs. However, our fertility specialists are here to help support you on your path to parenthood. We will help you assess your options if you are diagnosed with POI.