Diminished ovarian reserve (DOR), also called low ovarian reserve or low egg reserve means the decrease in ovary’s normal reproductive potential and fertility. As the age progresses, normally the number of eggs in the ovaries and the egg quality decreases. However, DOR is a condition where a woman has a low number of eggs in her ovaries but the quality of oocytes are high.
Sometimes due to certain diseases, injury, genetic factors or adverse environmental conditions, ovarian reserve is less than it should be at that age. The etiologic factors leading to DOR show a wide spectrum, ranging from previous ovarian surgery or chemotherapy to idiopathic premature ovarian failure.
Hormone tests (follicle stimulating hormone (FSH),Estradiol (E2),and anti-Mullerian hormone (AMH) measurements) and the measurement of antral follicle number (AFC) by ultrasound can give an idea about whether the patient will respond well, moderately or poorly to IVF and ovulation treatments. Many women who have diminished ovarian reserve have high FSH and/or low AMH levels. However, it is not possible to predict that pregnancy will not occur with any test result.
AMH is a protein produced by granulosa cells in ovarian follicles. A high amount of AMH indicates high number of eggs whereas low AMH levels show poor ovarian reserve. High AMH levels are associated with a better response to IVF medication. The success rate in IVF treatment corralates with the number of eggs collected at that treament cycle, therefore it’s beneficial to produce as many follicles as possible per IVF cycle.
Relatively high AMH level: polycystic ovary syndrome (PCOS)
Optimal AMH levels: (associated with increased fertility and better response rates to IVF and other fertility treatments):
Satisfactory AMH levels (basically: fine)
Low AMH levels (associated with a decreased number of follicles, but still have a good chance of getting pregnant – either naturally or through fertility treatment – especially if good-quality follicles present)
Very low AMH levels (all isn’t lost)
Note: the National Institute for Health and Care Excellence (NICE) specifies that less than 5.4 pmol/l will lead to a “low response”, and greater than or equal to 25.0 pmol/l will lead to a “high response”.
The level of AMH estimate the number of antral follicles in the ovaries; the more follicles a woman has, the more eggs she can release, provides an opportunity for a greater number of eggs to fertilize and develop into embryos and the better her chances of pregnancy. Women with lower AMH have lower antral follicular counts and produce a lower number of eggs. AMH levels do not reflect egg quality.
Women with very low AMH levels undergoing IVF still have reasonable chances of achieving a pregnancy, but their prognosis is significantly affected by chronological age.
In a study it was reported that serum AMH levels of >2.85 pmol/L is significantly lower live birth rates than those with higher AMH levels. They also suggested that every 0.71 pmol/L increase in AMH levels can cause a corresponding increase in clinical pregnancy rate.
One of the main tests of ovarian reserve is FSH. As age progresses, FSH values increase towards menopause. While FSH above 30 indicates definite menopause, FSH above 10 indicates that ovarian response will be less.
The E2 measurement does not add any additional contribution to the FSH measurement. High E2 can suppress FSH. An estradiol level of > 80 pg/ml can predict poor ovarian response. It has a low predictive value in terms of showing IVF successs. A cystic structure remaining from previous months may cause E2 to be measured higher.
On ultrasound image of an ovary the black spots are small cysts called antral follicles. Each follicle contains fluid, follicle cells and an egg. At the beginning of your cyle, when the follicles are small, the eggs inside are immature. It’s important for your doctor to count how many follicles are visible in each ovary. Women who have a lot of follicles are typically going to respond better to fertility medication and get more eggs than women who have fewer follicles. In fact, the dose of fertility medications in women who have a very high number of follicles should be reduced to prevent the complication called ovarian hyperstimulation syndrome (OHSS). Women who have few follicles will likely need a more aggressive medication protocol with higher doses of medication but may still get fewer eggs during IVF.
Detection of 6-10 antral follicles with a diameter of 2-10 mm in the ovaries on the 2nd or 3rd day of period by transvaginal ultrasonography means that the ovarian reserve is good.
While AFC has a good predictive value in showing ovarian reserve and ovarian response to ovulation treatments, it has low predictive value for egg quality and pregnancy outcomes. If the number of antral follicles is less than six, 75% of patients respond poorly to treatment. Antral follicle count and AMH are the strongest indicators of egg count and response to ovulation treatments.
Poor response to ovarian stimulation usually indicates decreased follicular response, resulting in a reduced number of retrieved oocytes. Poor ovarian response (POR) is diagnosed when at least two of the following three characteristics are present:
Two episodes of poor ovarian response after maximal stimulation in IVF treatment is sufficient to define a patient as a poor responder in the absence of advanced maternal age or an abnormal ovarian reserve test result.
No treatment can slow the decrease in the number of eggs and truly prevent diminished ovarian reserve. However, managing stress, having healthy diet, achieving a normal BMI (body mass index), boosting blood flow with sports, some vitamin supplements would some beneficial effects. Staying away from cigarettes will be helpful. Smoking permanently speeds up egg loss in the ovaries.
Women with DOR who want to conceive have options through fertility treatments. Woman with diminished ovarian reserve, can preserve her eggs by egg freezing. Fertility preservation involves retrieving a woman’s eggs from her ovaries and freezing them for later use. The best time for women to freeze eggs is when they are young and their ovarian reserve is better.
Women diagnosed with diminished ovarian reserve (DOR) have the same reduced success of conceiving with in vitro fertilization (IVF) treatment as they do with natural efforts to conceive. Patients with DOR is often characterized by poor fertility outcomes and a poor ovarian stimulation response to medicines used, a high cancellation rate of in an IVF treatment cycle, and a significant decline in pregnancy rates.
Almost all women who have very diminished ovarian reserve are told that donor eggs are their only treatment option and their only chance of having a baby. Although pregnancy rates with IVF are certainly low for patients with DOR, some of these patients can get pregnant with their own eggs after receiving appropriate, thoroughly individualized treatment.
Time is the most important factor with DOR treatment. The sooner the treatment be started, she will have the better treatment options and the higher pregnancy chances. Individualized treatment tailored to woman’s ovarian reserve status as well as any accompanying conditions affecting her fertility (like endometriosis or immunological issues) are very important factors to get a pregnancy.
The most important indicator for egg quality is the age of the woman. Low ovarian reserve is not an absolute indication that conception cannot be achieved, it alone does not prevent infertility treatment.