Diminished ovarian reserve refers to a clinical situation in which a woman’s ovaries do not contain as many oocytes as would be expected for her age. Ovarian reserve affects the ability to conceive and deliver a live birth.
One of the strongest predictors of ovarian reserve is a woman’s age. All women are born with a finite number of eggs, typically around one million. By the time puberty is reached the number of eggs is reduced to approximately 500,000. From puberty (around age 12) to menopause (around age 51+) there is a progressive depletion of egg number and quality in the ovaries, and therefore a decrease in ovarian reserve and reproductive potential. The rate of loss of oocytes within the ovary is genetically predetermined. Some women will experience a significant decline in the quantity of their oocytes in their forties, while others may experience this much earlier. Those women who experience premature decline are considered to have diminished ovarian reserve.
There are other causes of diminished ovarian reserve such as the ovary having been damaged or destroyed from a disease process such as endometriosis, ovarian tumours or autoimmune issues. Other factors may include exposure to certain chemotherapy agents or radiation treatment, ovarian surgery, and pelvic infection.
At Medfem Fertility Clinic, a routine part of the infertility evaluation includes comprehensive testing for ovarian reserve in order to determine a treatment course and to predict the likelihood of pregnancy with any specific treatment protocol. Multiple tests are available including cycle day 2/3 hormonal FSH and AMH testing, and transvaginal ultrasound evaluations to perform an antral follicle count as well as ovarian volume testing. The FSH level should be less than 10-12 miu/ml. An FSH greater than 18 miu/ml suggests a significant reduction in ovarian reserve with a corresponding marked reduction in the chance of achieving pregnancy, even with advanced fertility treatment. Ovarian reserve may also be determined by the outcome of ovarian hyperstimulation with gonadotropin hormones.
It is very difficult to adequately stimulate a woman’s ovary in the presence of diminished ovarian reserve, however, superovulation can increase the chance of conception in a treatment cycle by causing more oocytes to ovulate. In some cases it can prove very difficult to stimulate the ovaries, in which case there is limited ability to increase the chance of achieving pregnancy. If the diminished ovarian reserve is so significant that a woman cannot respond to superovulation then her best option for achieving a pregnancy is through the use of donor oocytes.
While diminished ovarian reserve does not eliminate the possibility of a pregnancy, it does reveal that the woman needs to be aggressive in her quest to become pregnant as time is clearly of the essence.
Premature Ovarian Failure
The average age of menopause is approximately 51 years of age. Premature ovarian failure is defined as the loss of ovarian function before age 35. Ovarian failure results from the loss of oocytes from the ovary, which leads to an inability of the ovary to produce estrogen, leading to a menopausal state. Common symptoms include the cessation of menses, and the development of hot flushes, night sweats, sleep disturbance, irritability and vaginal dryness. Hormonal tests may also show elevated FSH levels. Obviously, complete ovarian failure results in permanent infertility.
There are many causes for premature ovarian failure which can include autoimmune factors, genetic defects, endometriosis, ovarian tumours, chromosomal abnormalities such as Turner Syndrome, and cancer treatment (chemotherapy/radiation). In some cases premature ovarian failure is a result of genetically predetermined loss of a woman’s oocytes.
Though chances are very limited it may still be possible to fall pregnant with your own oocytes with aggressive fertility treatments. Fortunately, women with premature ovarian failure have an excellent chance of conceiving with egg donation.