Decreased ovarian reserve is a decrease in the quantity or quality of oocytes, leading to impaired fertility.
Ovarian reserve may begin to decrease at age 30 or even earlier and decreases rapidly after age 40. Ovarian lesions also decrease reserve. Although older age is a risk factor for decreased ovarian reserve, age and decreased ovarian reserve are each independent predictors of infertility and thus of a poorer response to fertility treatment.
Testing for decreased ovarian reserve is considered for women who are ≥ 35, who have had ovarian surgery, or who have responded poorly to treatments such as ovarian stimulation with exogenous gonadotropins. Follicle-stimulating hormone (FSH) levels > 10 mIU/mL or estradiol levels of < 80 pg/mL on day 3 of the menstrual cycle suggest the diagnosis. Diagnosis can also be made by giving the woman clomiphene 100 mg po once/day on days 5 to 9 of the menstrual cycle (clomiphene citrate challenge test). A dramatic increase in FSH and estradiol levels from day 3 to day 10 of the cycle indicates decreased reserve.
The AMH level is an early, reliable predictor of declining ovarian function. Increasingly, AMH measurement is used to assess ovarian reserve. A low AMH level predicts a lower chance of pregnancy after IVF; pregnancy is rare when the level is too low to be detected. The AFC is the total number of follicles that measure 2 to 10 mm (mean diameter) in both ovaries during the early follicular phase; AFC is determined by observation during transvaginal ultrasonography. If AFC is low (3 to 10), pregnancy after IVF is less likely.
Because pregnancy may still be possible, treatment is individualized based on the woman's circumstances and age. If women are > 42 or ovarian reserve is decreased, assisted reproduction using donor oocytes may be necessary.
Last full review/revision January 2013 by Robert W. Rebar, MD