Virginia Center for Reproductive Medicine
11150 Sunset Hills Rd
Reston, VA 20190
Assisted Reproductive Techniques (ART) – Part III
In Part III of this series, I will review one of the most common causes of infertility, the age factor, which is currently the most common cause of infertility in large cities. Women are waiting longer to have children, and for some this wait may unfortunately be too long.
The Egg Factor
Women are most fertile during their late teens and 20s, and for most women, getting pregnant becomes somewhat more difficult by their mid-30s, mainly because the number, and more importantly, the quality of eggs decreases as women age. Studies have shown that by age 37, eggs decrease in quality and numbers more quickly, and becoming pregnant becomes more difficult.
By the time women reach the age of 43 or 44 their chances of becoming pregnant are drastically reduced, about 1-2% even with the most aggressive therapy (most women older than 43 will require donor eggs to achieve a pregnancy). It is also true that over time the quality of eggs that are left in the ovaries becomes compromised. This means that the risk of having a miscarriage or a baby with birth defects increases significantly after the age of 35, and especially after 40.
Somewhat related to “age-factor infertility” is infertility related to a decline in “egg quality.” This certainly could be due to an age-related decline or to genetics or other unknown causes.
One of the screening tests that an infertility patient should perform is to check for the “ovarian reserve.” This involves a simple blood test for two hormones, FSH and estradiol, done on the third day of the menstrual cycle. The results of these tests could indicate a possible problem with egg production. Typically, FSH should be < 10 IU/L and estradiol less than 50 pg/ml. The interpretation of the results is also important.
For instance, if someones FSH is >10 IU/L, this could indicate that the ovaries may not respond adequately to fertility hormones, or that the quality of the eggs produced would not be adequate enough to yield a pregnancy.
For women older than 35, or whose ovaries appear small on ultrasound, or those whose ovaries contain a low number of early follicles, a more definitive test is ordered. This test is the Clomid challenge test (CCCT), which involves the administration of a weak fertility drug (Clomid) for five days followed by repeating the FSH level on day 10. Women with adequate ovarian reserve should have a lower day-10 FSH level compared to day three.
In general, if this hormone screening is abnormal, the patient has to be aggressive by resorting to IVF. Even with such treatment, however, pregnancy rates could be significantly lower in these patients. The main reason why IVF is again the best treatment option in women with borderline elevated FSH levels, is the fact that more than one embryo (if available) would be transferred, thus increasing the odds that one of these embryos may implant.
In addition, during the IVF process, assisted hatching could be performed to improve the chances of implantation. The latter is performed since it is believed that women who have elevated FSH levels also produce eggs with harder or thicker shells.
In some patients, FSH is so elevated that it might not be cost-effective to attempt an IVF cycle and to resort directly to egg donation.
It is also important to remember that these tests (FSH/estradiol) could erroneously indicate a problem and the only way to ascertain the validity of the result is to attempt a treatment cycle by taking fertility hormones and checking to see whether the ovaries would respond adequately.