Women are born with all the oocytes (eggs) that they will have for their lifetime â this is your âovarian reserve.â As women age, this ovarian reserve slowly decreases as oocytes are recruited and used during the menstrual cycle.
Once the ovarian reserve has been depleted, menopause will occur. There are two common ways of measuring the ovarian reserve: first with an ultrasound and second with blood testing, measuring you Anti-Mullerian Hormone (AMH) and/or your Follicle Stimulating Hormone (FSH).
The ultrasound should be performed between cycle day 2-5 and will count the number of resting follicles (cysts containing oocytes) within the ovary.
The Anti-Mullerian hormone (AMH) is a hormone created by the resting oocytes within the ovary. AMH levels can be drawn at any time during a menstrual cycle. The levels can be affected by current or recent long term birth control use. Fertility specialists use the AMH by comparing it to known âaverage levelsâ based on a womanâs age. The higher the AMH, the greater the number of oocytes present. The AMH level is helpful when determining medication doses during fertility treatments but is NOT correlated with a personâs ability to become pregnant.
Finally, FSH can be drawn in conjunction with Estradiol on cycle day 2-4 to measure ovarian reserve. Elevations in FSH when the ovary is at rest (low Estradiol levels) indicate that the brain is working harder than normal to force the ovary to start producing an egg.
Together, these two tests can be used to determine waning ovarian function, indirectly indicating a lower ovarian reserve.
More detailed information on ovarian reserve testing can be found at www.reproductivefacts.org