Many women have heard of the infamous reproductive "biological clock," but they may not know that it's very real. Aging is a normal, inevitable process. As you get older, your fertility declines due to age-related changes in the ovaries. A woman is born with all the eggs she will ever have, unlike men who continue to produce sperm throughout their lives. Of the eggs remaining at puberty, only about 200 will ovulate during all reproductive years and the rest will undergo atresia. Atresia is a degenerative process that occurs regardless of whether you are pregnant, have regular menstrual cycles, use birth control, or undergo infertility treatment. Smoking appears to accelerate atresia and is associated with early menopause.
Unfortunately the outward signs of a woman's reproductive potential are few to none. The chance of conception generally begins to decline around age 30, although it can start earlier in some women. At age 30, a healthy, fertile woman has a 20% chance of success in a month of trying. By the age of 40, this probability has dropped to just 5%. In rare cases, a woman may have premature ovarian failure, and her ovaries may stop producing eggs much earlier, perhaps in her late 20s. Not only does a woman's reproductive potential decline with age, but so does the chance for shedding increases. This increase is probably due to the quality of eggs (increased number of abnormal eggs) she produces as she grows older.
Ovarian reserve
Ovarian reserve refers to the quality and quantity of eggs in the ovaries and how well they respond to the hormonal signals they receive from the brain. Ovarian reserve can be assessed through a simple blood test and ultrasound. The blood test is used to measure the hormones FSH (follicle-stimulating hormone), LH (luteinizing hormone) and estradiol on day 2, 3 or 4 of the cycle (day 1 is the first day of full menstrual flow). High FSH levels indicate that your ovarian reserve is low and therefore the chances of conception are low. Your doctor may also perform an ultrasound to measure the number of small or "carbonate" follicles in your ovaries. A low follicle count predicts an increased likelihood of poor response to treatment and a decreased likelihood of a live birth.
Treatment
There are many different treatments for infertility. Deciding to pursue infertility treatment is an important decision and should be discussed with your partner and your doctor. As a woman ages, not only does a woman's fertility potential decrease, but effective treatment options also become limited. Traditional hormonal ovarian stimulation combined with intrauterine insemination may be the preferred treatment for some patients under 40, but is much less effective in women over 40. IVF is the most effective treatment for women of any reproductive age, but the live birth rate for women using their own eggs for IVF drops significantly in women over 40. IVF success rates in women over 40 are significantly increased with the use of a young egg donor. While age can have a dramatic effect on the ovaries and the eggs produced, a woman's uterus in her 40s is usually as good as a younger woman's. However, many women would prefer to use their own eggs instead of an egg donor, and therefore should start trying to conceive well before the age of 40.
Conclusion
Aging has a profound effect on all of us. Signs of aging in a woman's reproductive capacity can be subtle or completely hidden. Women need to understand that ovarian decline is a normal and ongoing process as they plan for their future. Unfortunately, there is no treatment that can restore eggs or improve their quality. Therefore, it is important for women to be aware of the potential effects of aging on their fertility, including a general decrease in fertility, a greater risk of miscarriage, and a greater risk of chromosomal abnormalities in newborns.
If you are concerned about your reproductive potential or are having difficulty getting pregnant, contact the Center for Reproductive Medicine and Fetal Medicine “Dr. Alexandros Traianos” to schedule an appointment.