Poor ovarian reserve


Poor ovarian reserve is a condition of low fertility characterized by 1): low numbers of remaining oocytes in the ovaries or 2) possibly impaired preantral oocyte development or recruitment. Recent research suggests that premature ovarian aging and premature ovarian failure may represent a continuum of premature ovarian senescence. It is usually accompanied by high FSH levels.
Quality of the eggs may also be impaired. However, other studies show no association with elevated FSH levels and genetic quality of embryos after adjusting for age. The decline in quality was age related, not FSH related as the younger women with high day three FSH levels had higher live birth rates than the older women with high FSH. There was no significant difference in genetic embryo quality between same aged women regardless of FSH levels. A 2008 study concluded that diminished reserve did not affect the quality of oocytes and any reduction in quality in diminished reserve women was age related. One expert concluded: in young women with poor reserve when eggs are obtained they have near normal rates of implantation and pregnancy rates, but they are at high risk for IVF cancellation; if eggs are obtained, pregnancy rates are typically better than in older woman with normal reserve. However, if the FSH level is extremely elevated these conclusions are likely not applicable.

Cause

There is some controversy as the accuracy of the tests used to predict poor ovarian reserve. One systematic review concluded that the accuracy of predicting the occurrence of pregnancy is very limited. When a high threshold is used, to prevent couples from wrongly being refused IVF, only approximately 3% of IVF-indicated cases are identified as having unfavourable prospects in an IVF treatment cycle. Also, the review concluded the use of any ORT for outcome prediction cannot be supported. Also Centers for Disease Control and Prevention statistics show that the success rates for IVF with diminished ovarian reserve vary widely between IVF centers.

Follicle stimulating hormone

Elevated serum follicle stimulating hormone level measured on day three of the menstrual cycle. If a lower value occurs from later testing, the highest value is considered the most predictive. FSH assays can differ somewhat so reference ranges as to what is normal, premenopausal or menopausal should be based on ranges provided by the laboratory doing the testing. Estradiol should also be measured as women who ovulate early may have elevated E2 levels above 80 pg/mL which will mask an elevated FSH level and give a false negative result.
High FSH strongly predicts poor IVF response in older women, less so in younger women. One study showed an elevated basal day-three FSH is correlated with diminished ovarian reserve in women aged over 35 years and is associated with poor pregnancy rates after treatment of ovulation induction.
The rates for spontaneous pregnancy in older women with elevated FSH levels have not been studied very well and the spontaneous pregnancy success rate, while low, may be underestimated due to non reporting bias, as most infertility clinics will not accept women over the age of forty with FSH levels in the premenopausal range or higher.
A woman can have a normal day-three FSH level yet still respond poorly to ovarian stimulation and hence can be considered to have poor reserve. Thus, another FSH-based test is often used to detect poor ovarian reserve: the clomid challenge test, also known as CCCT.

Antral follicle count

Transvaginal ultrasonography can be used to determine antral follicle count. This is an easy-to-perform and noninvasive method. Several studies show this test to be more accurate than basal FSH testing for older women in predicting IVF outcome. This method of determining ovarian reserve is recommended by Dr. Sherman J. Silber, author and medical director of the Infertility Center of St. Louis.


AFC and Median Fertile Years Remaining
Antral Follicle Count
Median Years to Last ChildMedian Years to Menopause
5__7.3
104.212.9
159.318.4
2014.824.0

Note, the above table from Silber's book may be in error as it has no basis in any scientific study, and contradicts data from Broekmans, et al. 2004 study. The above table closely matches Broekmans' data only if interpreted as the total AFC of both ovaries. Only antral follicles that were 2–10 mm in size were counted in Broekmans' study.
Age and AFC and Age of Loss of Natural Fertility
Antral Follicle Count
Age at Time of CountAge of Loss of Natural Fertility
63029–33
63533–38
64038–41
103033–38
103538–41
153038–41

AFC and FSH Stimulation Recommendations for Cycles Using Assisted Reproduction Technology
Antral Follicle CountSignificance
< 4Poor reserve
4–7Low count, high dosage of FSH required
8–12Slightly reduced reserve
> 12Normal

Other

Variable success rate with treatment, very few controlled studies, mostly case reports. Treatment success strongly tends to diminish with age and degree of elevation of FSH.
While the primary cause of the end to menstrual cycles is the exhaustion of ovarian follicles, there is some evidence that a defect in the hypothalamus is critical in the transition from regular to irregular cycles. This is supported by at least one study in which transplantation of ovaries from old rats to young ovariectomized rats resulted in follicular development and ovulation. Also, electrical stimulation of the hypothalamus is capable of restoring reproductive function in aged animals. Due to the complex interrelationship among the hypothalamus, pituitary and ovaries defects in the functioning of one level can cause defects on the other levels.

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