30 August 2007

Ovarian Reserve Testing

The term 'Ovarian Reserve' refers to a woman's reproductive potential with respect to the number of eggs in the ovary and the quality of those eggs.

Once the eggs are outside the body and under the microscope its obviously easier to speak about its quality but the whole idea is to be able to predict the outcome even without handling the eggs. The following are used:

Age: Age as discussed earlier is in itself a predictor of the outcome. The chances of getting good number and quality of eggs after the age of 40 are quite remote. Although even spontaneous pregnancies do happen they cannot be used as a yardstick to treat women at higher age groups.

Antral Follicle Count: As I have said before, women recruit about 15 to 20 eggs just before the beginning of each menstrual cycle. Of these, depending on the stimulation given, one or many will eventually grow to mature size. This baseline pool of eggs can be counted on Day 2 or 3 of the periods by Trans Vaginal Ultrasound. If more than 5 are present then the woman stands a good chance to produce eggs with stimulation.

Baseline FSH and Estradiol (E2) levels: As normal values(done on Day 2 or 3 of periods), the FSH levels should be less than 10 and E2 levels between 20 and 80pg/ml. FSH levels are one of the earliest parameters to rise, long before the eggs actually finish. To give you an idea, you can imagine FSH to be the whip which stimulates the ovary to produce eggs. Under normal circumstances, less whipping is required and the levels of FSH are thus low. When the ovary is failing, the whipping required is far greater resulting in high FSH levels. Sometimes the FSH levels tend to fluctuate between abnormal (high) and normal (low) levels. However one must remember that even a single FSH level above 10 means that the eggs may not be of very good quality, even though the levels may come down later.

Clomiphene Challenge Test: In this test the baseline FSH is tested on Day 3. Thereafter Clomiphene Citrate 100mg tablets are given orally from Day 5 to Day 9 of the periods. Fsh values are again tested on Day 10 of periods. A normal value would be to have both Day 3 and Day 10 FSH values to be below 10.

Inhibin levels: While FSH tends to rise in ageing women, the Inhibin levels tend to fall. Infact it has been suggested that Inhibin levels are more sensitive and detect more subtle changes than baseline FSH levels. However as the test is still experimental, not widely available and quite expensive, it is not used in routine practise.

Thse are the common parameters used by us in day to day practise but like they say "nothing prepares you for life' similarly nothing can predict how the ovary will ultimately behave once we start to stimulate it. Well either as doctors we dont yet know the whole story or as we commonly say' maybe there is someone else above us all who controls everything'.

1 comment:

ishani said...

ok doc, this is unrelated to ovarian reserve testing but thought you could write about egg/sperm donation and surrogacy (in India)...these concepts are still not too widely discussed and known in India and infact have heard many a patient of yours discussing the same while waiting at careivf!:-)