Diminished Ovarian Reserve (DOR)

What ovarian reserve means

A woman is born with all the eggs she will ever have, about 1 to 2 million. By puberty roughly 300,000 to 400,000 remain, and the number falls steadily, accelerating after about age 35, until menopause. Ovarian reserve is a measure of how many eggs remain.

Two things affect fertility:

• Quantity: the number of eggs, reflected by ovarian reserve tests
• Quality: the chance an egg is chromosomally normal, which depends mainly on age

DOR describes low quantity. A 30-year-old with low AMH usually has better egg quality than a 42-year-old with normal AMH.

Tests for ovarian reserve

What is a low AMH?

AMH normally falls with age. Cutoffs vary by lab, but values below about 1.0 ng/mL are often considered low and below about 0.5 ng/mL very low, especially for IVF planning. Results must be read against your age.

What the tests can and cannot tell you

ASRM and ACOG note that ovarian reserve tests:

• do predict how many eggs are likely to be retrieved during IVF stimulation
• do not reliably predict whether you will get pregnant naturally in the next year
• do not measure egg quality
• should not be used alone to deny fertility treatment

Causes and risk factors

• Age: the most common reason
• Endometriosis, especially ovarian cysts (endometriomas) and their surgical removal
• Ovarian surgery
• Chemotherapy and pelvic radiation
• Smoking, which brings menopause forward by 1 to 2 years
• Genetic factors: fragile X premutation carriers, Turner syndrome mosaicism, family history of early menopause
• Autoimmune conditions
• often no cause is found

Symptoms

Most women with DOR have no symptoms and regular periods. Clues may include:

• difficulty getting pregnant
• shorter cycles (under 25 days) or periods becoming irregular
• few eggs retrieved in a previous IVF cycle

When reserve is very low before age 40 with absent or irregular periods and menopausal-level FSH, the diagnosis becomes premature ovarian insufficiency, which differs from DOR.

Diagnosis and evaluation

Evaluation is usually part of a full infertility workup, which also checks ovulation, the fallopian tubes (hysterosalpingogram), the uterus and the male partner's semen analysis. Women with very low reserve at a young age may be offered fragile X premutation testing and chromosome analysis.

Fertility options

Natural conception and timing

Women with low AMH but regular ovulation often still conceive naturally. Because time matters, specialists usually recommend evaluation sooner rather than waiting.

Ovulation induction with IUI

Oral medicines (letrozole or clomiphene) or injections with intrauterine insemination may be used, especially in younger women.

IVF

IVF with higher-dose stimulation or adjusted protocols. Fewer eggs are retrieved, so success per cycle is lower and multiple cycles may be needed. Success depends strongly on age.

Egg freezing

Women not ready to conceive may consider freezing eggs, ideally before age 35 to 38, accepting that low reserve means fewer eggs per cycle.

Donor eggs

Donor egg IVF offers the highest success rates when reserve is very low or previous cycles have failed, because pregnancy chances depend on the donor's age.

Adjuncts

DHEA, coenzyme Q10 and growth hormone are sometimes used, but evidence of benefit is limited. Discuss them with your specialist.

Living with a diagnosis of DOR

A low AMH result can be distressing. Remember that it reflects egg numbers, not your overall health or a guarantee of infertility. Stopping smoking, keeping a healthy weight and seeking timely fertility advice are the most useful steps. Counseling and support groups can help.

Frequently asked questions

Can I get pregnant with diminished ovarian reserve?

Yes. Many women with low AMH conceive naturally, because pregnancy depends mainly on egg quality, which is tied to age. DOR does reduce the number of eggs available for IVF. Seeing a fertility specialist early helps you use the time you have.

What AMH level is considered low?

Labs differ, but an AMH below about 1.0 ng/mL is often considered low and below about 0.5 ng/mL very low, especially in the context of IVF. AMH falls naturally with age, so results are always interpreted for your age.

Can ovarian reserve be improved?

The number of eggs cannot be increased. Stopping smoking and avoiding unnecessary ovarian surgery help preserve what remains. Supplements such as DHEA or CoQ10 are sometimes tried, but evidence is limited.

Does diminished ovarian reserve mean early menopause?

Not necessarily, though very low reserve at a young age can be followed by earlier menopause. Premature ovarian insufficiency is a different diagnosis, with irregular or absent periods and menopausal hormone levels before 40.