A woman's age can be a significant factor in infertility. Women start out with all the eggs (oocytes) they'll ever have at birth - about 2 million, which remain dormant in fluid-filled cavities in the ovaries (follicles) until they are released. Those that are not released gradually fade away as a woman ages. While less than 400,000 eggs remain by menopause usually only one egg is released during each menstrual cycle.

• Women are at their most fertile up to age 30
• Ovarian reserve is diminished by the early 30's
• By age 35 there is much less time to address female infertility
• Menopause occurs normally in women as young as 40, although the average age is 50

Diminished ovarian reserve (egg reserve) is associated with a lower chance of getting pregnant and a higher chance of spontaneous miscarriage. Some women have a fluctuation in their hormonal levels from cycle to cycle. The Clomiphene Citrate (Clomid) Challenge Test may be used to examine ovarian reserve.