Overview
Diminished Ovarian Reserve (DOR) is a condition in which the number of remaining eggs in the ovaries is lower than expected for a woman's age, reducing fertility and making conception more challenging. Although it is more common with advancing age, DOR can also occur due to genetic factors, medical conditions, autoimmune disorders, or previous ovarian surgeries. Treatment is tailored to a woman's age, ovarian reserve, and reproductive goals and may include fertility medications, lifestyle modifications, and assisted reproductive techniques such as IVF to improve the chances of pregnancy.
Table of Contents
- What Does Diminished Ovarian Reserve Mean?
- What are the major causes of DOR?
- What are the Types of Diminished Ovarian Reserve?
- Diminished Ovarian Reserve Treatment
- Is It Possible to Get Pregnant With Low Egg Count?
- When Getting Pregnant With DOR is Not Possible?
- DOR Vs. Premature Ovarian Insufficiency
- Conclusion
What Does Diminished Ovarian Reserve Mean?
Women are born with about 6 million eggs, and during their lifetime, no new egg cells are formed. In their 20s, the egg count is around 100,000 to 200,000, remaining within the ovaries. As they age, the egg count continues to decrease to the point where fertilisation is no longer possible. The process driving this is known as atresia. It is a form of programmed cell death in which cells break down and are absorbed by the body.
A reduction in egg count is called Diminished Ovarian Reserve (DOR). It is also known as low egg count or low ovarian reserve. The eggs are the most important part of pregnancy, and of course, sperm are, too. But if there’s a low egg count or if the ovary produces fewer eggs, the sperm may not be able to fertilise the egg. This leads to an unsuccessful pregnancy.
In addition to the quantity of eggs, this condition also refers to their quality. This can occur in women nearing menopause, but the rate of decline may vary, depending on other factors, such as genetic abnormalities, medical treatments, injury, and even surgery.
Note: Just because a woman has a low egg count doesn’t mean getting pregnant is not possible. It just means getting pregnant might become difficult, which requires fertility treatment interventions.
What are the major causes of DOR?
Diminished ovarian reserve may result from biological, genetic, medical, or environmental causes. Understanding these helps people know who is at risk and what can be done:
Age
After 35, the rate of follicle loss and decrease in egg quality begins rapidly. This increases the risk of a bad response to stimulation, resulting in lower success with natural conception and earlier menopause.
Genetic Factors
Genetics is another possible cause, as it may impact the ovarian reserve. Conditions like Fragile X permutation carriers and chromosomal abnormalities are known to cause POI (primary ovarian insufficiency). As a result, the ovaries may not function properly. Research is ongoing to understand which other genes may influence the decline in the egg reserve.
Medical History
Surgical history, such as ovarian surgery, especially cystectomy or partial oophorectomy, can cause the depletion of ovarian reserve. Another medical cause is the underlying conditions, such as untreated thyroid disorders and autoimmune diseases, that can disrupt the ovarian signalling. Also, endometriosis and pelvic inflammatory disease can damage ovarian tissue. While PCOS affects ovulation, it is not typically associated with diminished ovarian reserve.
Environment
The environment in which a woman lives, her habits, lifestyle, and diet can all affect ovarian health and egg reserve. Exposure to certain chemicals or toxins, such as tobacco and alcohol, can damage the ovaries, which reduces the number of eggs at one time. Even a woman being undernourished can rapidly reduce her egg count.
Note: Sometimes the condition is caused by no apparent cause (Idiopathic).
What are the Types of Diminished Ovarian Reserve?
Here is a table explaining the types of DOR -
Type | Key Feature | Trigger |
Age-Related DOR | Natural decline in the reserve with age, which makes conception more challenging | >35 years, may vary |
Premature DOR | Decline starts early, before age 35. This might also happen in the 20s or 30s. | Genetic factors, environment, lifestyle |
Latrogenic DOR | Usually induced medically, for example, chemotherapy or radiation therapy. This can be permanent or temporary, depending on the person's health and the treatment. | After the treatment exposure |
Idiopathic DOR | There are no identifiable causes till now. | Might happen at any age |
Diminished Ovarian Reserve Treatment
Treatment for Diminished Ovarian Reserve uses several methods. Say,assisted reproductive techniques, hormone therapies, nutraceuticals, and even regenerative medicines. The goal of the treatment is to stimulate the ovaries and improve ovarian function, so that pregnancy can happen without any further challenges.
Here are some treatment methods for low egg count in the ovarian reserve:
Hormonal Therapies
Hormonal therapies are considered to improve ovarian response. Here are three therapies used for this purpose:
- Testosterone Supplementation: These supplements are known to increase the rate of live birth and also the egg quantity in women with DOR.
- Dehydroepiandrosterone (DHEA) is said to increase the number of eggs and is also used as a pre-treatment.
- Gonadotropin Protocols: Both strong and lower doses of medications during fertility treatment, and high dosages can help produce more eggs in women with low ovarian reserve.
Ovarian Stimulation and Assisted Reproduction
Ovarian stimulation is one of the most commonfertility treatment approaches for DOR. Doctors give fertility medication to the patient so that the ovaries can be well-stimulated to produce multiple eggs during a single cycle. This improves the chance of fertilisation through assisted reproduction treatment.
Since everybody is different, the reaction to the medication varies too, so doctors customise the medication type, dosage, timing, and frequency. Here are some assisted methods doctors may use -
- Donor Eggs: If the quality or quantity of the patient’s eggs is poor, doctors use adonor egg and fertilise it with the partner’s sperm in a lab. The fertilised embryo is then transferred to the uterus, where it attaches itself to the lining.
- Patient’s Eggs: Patients can consider freezing their eggs to preserve fertility. If the healthcare provider feels that the woman is at risk for DOR, they might suggest freezing the eggs to ensure that there is a good-quality egg available for the sperm to fertilise. Sometimes doctors may also suggest freezing embryos for later use.
- Embryo Adoption: Embryo adoption is an option when a woman is DOR and is completely unable to conceive using her own eggs. In this case, patients can use frozen embryos that are usually donated by another couple. The donor embryo is then transferred to the uterus using assisted reproductive techniques. As the embryo is fertilised, this may increase the chance of getting pregnant.
Platelet-Rich Plasma Therapy
Platelet-rich plasma therapy, also known as PRP therapy, uses the patient’s own platelets in the ovary. A recent meta-analysis suggests that this approach has significantly improved AMH, antral follicle count, and clinical pregnancy rates. It also helped to increase live birth rates.
Lifestyle Changes and Experimental Approaches
Although not a standard treatment, it is used in addition to other treatments. This might include avoiding environmental toxins, stopping or reducing smoking, limiting alcohol intake, and managing stress.
Doing this can improve the overall health of the ovarian reserve. Though one cannot completely prevent the eggs from being depleted, it gives enough time to make treatment decisions mindfully. Also, researchers are still studying how gene-targeted therapies and regenerative medicine techniques can help improve ovarian function.
Is It Possible to Get Pregnant With Low Egg Count?
As mentioned above, having a low egg count does not strip a person of their ability to get pregnant. However, the odds of conceiving may be smaller. Many women with DOR are still able to conceive either naturally or with the help of fertility treatments.
Egg count is not the only factor in getting pregnant; sperm quality, along with egg quality and quantity and overall reproductive health, also determines whether a person can get pregnant. In many cases, young women with low ovarian reserve may still have healthy eggs. This can improve their chances of conceiving.
When Getting Pregnant With DOR is Not Possible?
People with DOR might have difficulty conceiving if both egg quality and quantity are severely poor. While through ART, pregnancies might still be possible, there are cases where conception may have a low success chance, even with assisted methods. It may become difficult or unlikely to get pregnant when:
- The ovaries stop producing healthy eggs
- AMH level is extremely low
- Repeated yet failed IVF procedures due to poor egg response
- Premature ovarian insufficiency
Other fertility issues, such as blocked fallopian tubes, severe endometriosis, etc, along with DOR, can also make conceiving challenging.
Note: In the above cases, doctors may suggest opting for donor eggs, embryo donation, or adoption.
DOR Vs. Premature Ovarian Insufficiency
Feature | Diminished Ovarian Reserve (DOR) | Premature Ovarian Insufficiency (POI) |
Definition | A reduction in the quantity (and often quality) of remaining eggs compared to what is typically expected for a woman's age. | A clinical condition where the ovaries stop functioning normally, leading to depleted estrogen production before the age of 40. |
Menstrual Cycle Status | Menstrual cycles are typically regular, though they may become slightly shorter (e.g., 21–25 days) as the condition advances. | Menstrual cycles are highly irregular, sporadic, or stop entirely (amenorrhea) for 4 months or more. |
Hormonal Profile |
|
|
Systemic Symptoms | Typically asymptomatic. It is most often diagnosed during a fertility workup when a patient is struggling to conceive. | Causes menopausal symptoms, mainly due to severe estrogen deficiency, including hot flashes, night sweats, in addition to vaginal dryness and mood changes. |
Primary Treatment Focus | Focused primarily on fertility, such as attempts to conceive naturally, ovary stimulation to produce more eggs in one cycle for IVF, or fertility preservation (egg/embryo freezing) for later. | Hormone Replacement Therapy (HRT) is standard until the natural age of menopause (~51) to protect bone and heart health. |
Pregnancy Potential | Natural conception is still highly possible, though it may take longer. IVF with a patient's own eggs is a viable path, though yield may be lower. | Natural conception is rare (about a 5% to 10% chance due to sporadic ovulation). Oocyte (egg) donation or embryo adoption are the primary paths to pregnancy. |
Conclusion
Diminished Ovarian Reserve is a term for a low number of eggs in the ovaries. It also means that the quality of the egg is depleting. There can be several causes of the condition, and the major ones are genetic factors, age, and medical conditions. This may lead to a problematic pregnancy. However, this does not indicate that a woman can never be pregnant.
With the advancement in technology and treatment options, such as assisted reproduction treatment using one's own or donor eggs, it is very helpful. Sometimes patients also have to opt for embryo donation if the woman's eggs are of low or poor quality. In addition, doctors suggest lifestyle changes, adjustments to sleep patterns, and dietary changes to improve the success rate of the treatment.