Diminished Ovarian Reserve - What is DOR?


Medically reviewed by Norbert Gleicher, MD, FACOG, FACS - Written by CHR Staff - Updated on Apr 22, 2019

What is Ovarian Reserve?

The ability of a woman's ovaries to produce high-quality eggs (and ultimately good-quality embryos) is known as ovarian reserve (OR). OR declines naturally as women age, but some women experience a decline of ovarian reserve sooner than others.

What is DOR?

One of the major conditions leading to infertility in women, DOR (meaning diminished ovarian reserve) is characterized by a low number of eggs in a woman's ovaries and/or impaired development of the existing eggs. This is why the lay public sometimes call DOR “low egg reserve” colloquially. CHR has special expertise in treating women with DOR, born out of our decade-long research on the condition.

CHR Explains


DOR: Meaning for Patients, and Prognosis for Fertility

What does low ovarian reserve mean for fertility? Women with untreated DOR have a difficult time conceiving. Moreover, when they do conceive, they experience the highest miscarriage rates of any infertility diagnosis. This is because approximately 95 percent of embryo quality comes from the eggs. Poor-quality embryos are less likely to develop and implant in the uterus, and more likely to result in miscarriages even when they implant.

Diminished Ovarian Reserve and Natural Pregnancy

DOR, especially very low ovarian reserve, makes it difficult for a woman to get pregnant naturally. When a woman has a low number of eggs in her ovaries, she may not ovulate every month, which can seriously reduce her chances of conceiving from intercourse alone. Furthermore, egg quality and quantity usually go hand in hand, meaning that a woman with DOR has both low number of eggs and low-quality eggs. Just how hard it is for a woman with DOR to get pregnant naturally will depend on the severity of the problem. In order to conceive, many women with DOR need ovarian stimulation to treat her diminished egg reserve with androgen (DHEA) supplementation followed by in vitro fertilization (IVF).

"CHR has led decades of research and pioneered the use of DHEA, now a key treatment for DOR."

Dr. Norbert Gleicher

Dr. Norbert Gleicher

What Does Low Egg Reserve Mean For Women Under 40?

Diminished ovarian reserve is a natural consequence of aging, as women get older.
Women attempting pregnancy after age 40 often have difficulty getting pregnant for this reason.
However, DOR is not a condition exclusive to women over 40. It can affect younger women as well.

Approximately 10 percent of women begin this usually age-related decline of ovarian function much earlier in life. When their ovarian reserve is evaluated, it is found to be lower than what is expected for their age. These women are considered to suffer from premature ovarian aging (POA) a clinical term coined by CHR researchers. Like older women with age-related DOR, women with POA have a hard time conceiving on their own and even with fertility treatments, as they are often misdiagnosed and given inappropriate treatments for their ovarian reserve status. However, with appropriate premature ovarian aging diagnosis and POA treatment, many of CHR's POA patients have been able to successfully conceive.

Causes of Poor Ovarian Reserve

When initially diagnosed with poor ovarian reserve, many of our patients ask, “What causes low ovarian reserve?” DOR may be a part of the natural aging process; in other women, especially those with POA, it may have an autoimmune etiology; we also suspect there is a genetic component when DOR develops prematurely. With DOR, it is crucial that your fertility specialist recommend appropriate ovarian reserve testing for proper diagnosis, and suggest diminished ovarian reserve treatment.

Diminished Ovarian Reserve Symptoms

Diminished ovarian reserve often does not have any symptoms, and patients are unaware that they have DOR. The most common low ovarian reserve symptoms, when present, are missing or irregular periods. Difficulty conceiving, as well as repeated miscarriages, are often the only outward signal that DOR may be involved.

Because DOR symptoms are often absent, testing is imperative when a woman has trouble conceiving. The best method to diagnose low ovarian reserve is to perform a blood test that checks for a woman’s level of follicle stimulating hormone (FSH) and anti mullerian hormone (AMH). Elevated FSH levels and low AMH levels are an indicator that the ovarian reserve is becoming depleted. Antral follicle count (AFC) is sometimes used to evaluate ovarian reserve, but AFC is not as reliable as FSH and AMH.

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Norbert Gleicher, MD

Norbert Gleicher, MD, FACOG, FACS

Norbert Gleicher, MD, leads CHR’s clinical and research efforts as Medical Director and Chief Scientist. A world-renowned specialist in reproductive endocrinology, Dr. Gleicher has published hundreds of peer-reviewed papers and lectured globally while keeping an active clinical career focused on ovarian aging, immunological issues and other difficult cases of infertility.

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