Understanding Diminished Ovarian Reserve

Every person with ovaries loses eggs as they age, and about 10-20% of people with ovaries experience diminshed ovarian reserve (DOR) before age 40. In addition, about 1 in 100 people with ovaries will experience premature menopause before age 40 (also known as premature ovarian failure or POF).

The chances of unassisted pregnancy decline as a person ages and ovarian reserve declines, but there are several fertility treatments that can help patients with diminished ovarian reserve get pregnant.

WHAT IS DIMINISHED OVARIAN RESERVE (DOR)?

Diminished ovarian reserve is a decline in the reproductive potential of a person’s ovaries, often due to age. People with ovaries are born with a fixed amount of eggs, and this number naturally declines following the peak reproductive years -which are between the late teens and early 20s.

Some medical conditions and genetic disorders can cause some people to experience DOR or early menopause at a younger-than-expected age.

HOW DOES DIMINISHED OVARIAN RESERVE (DOR) AFFECT FERTILITY?

Diminished ovarian reserve (DOR) relates directly to the quality of the remaining eggs in the ovaries. As egg count decreases, so does the likelihood of producing high-quality eggs that can be fertilized, becoming high-quality embryos that can survive the initial days of development and develop into a healthy pregnancy.

As a person ages, their ability to produce high-quality eggs diminishes, and they also have fewer eggs in general. However, quantity does not always mean quality; some people who have a small number of high-quality eggs go on to achieve a live birth, either unassisted or using assisted reproductive technologies

While lower egg numbers alone are not associated with infertility in patients who ovulate regularly, patients with DOR will have a lower response to stimulating medications in IVF, meaning a lower number of eggs will be retrieved, despite high doses of medication. Lower egg numbers may result in lower live birth rates in IVF. 

HOW IS DIMINISHED OVARIAN RESERVE (DOR) DIAGNOSED?

A person’s ovarian reserve can be measured through a combination of blood hormone testing and a transvaginal ultrasound.

The blood test measures several hormones on day 2-4 of a person’s menstrual cycle: Follicle Stimulating Hormone (FSH), estradiol levels (E2), and anti-Müllerian Hormone (AMH). 

FSH is produced by the pituitary gland in the brain and signals to the ovary to develop a follicle for ovulation.  AMH is produced by granulosa cells in smaller (pre-antral) follicles and may be the most accurate reflection of egg numbers. A high FSH and/or a low AMH level suggests that a person has diminished ovarian reserve or low egg count and will have a lower response to stimulating medications in IVF.

The ultrasound procedure, called an antral follicle count, counts visible ovarian follicles on days 2-4 of the menstrual cycle to further estimate the ovarian egg reserve. 

WHAT ELSE SHOULD I KNOW ABOUT TREATMENT FOR DIMINISHED OVARIAN RESERVE (DOR)? 

No treatments exist for reversing DOR, however, scientists continue to study treatment options to preserve ovarian function. A person who is diagnosed with DOR but is not yet ready to start a family may consider egg freezing. 

A decline in egg quality is largely related to an increase in genetically abnormal eggs which, in turn, increases the risk of chromosomal abnormalities in embryos. Therefore, preimplantation genetic testing (PGT) can help your care team select embryos with a normal number of chromosomes for embryo transfer.

PGT is especially beneficial for people aged 38 and older or those who have already experienced failed IVF cycles. IVF using donor eggs is another treatment option.