Advanced Maternal Age

More women are choosing to delay childbearing until their late 30s and early 40s. Studies have demonstrated that almost half of women older than 40 will experience infertility. Naturally-occurring fertility levels decrease with advancing age, so prompt evaluation and aggressive treatment are important considerations for these women.

Fertility and Age

Numerous studies point to a consistent decline in fecundity (the chance to conceive in any given month) with increasing age. Even if all fertility factors are optimal, the average 25 year old woman may have a 25 percent chance per month for getting pregnant. The average 40 year old woman has only a five percent per month chance for conception.

In addition to decreasing fecundity, older women experience an increased incidence of miscarriage. Women over age 40 have approximately a one-in-three chance of having a miscarriage in any given pregnancy. In addition, one in 60 live births to 40 year old women are genetically abnormal.

Though many possible reasons exists, this age-associated decline in fertility (and increase in miscarriages) is largely due to abnormalities in the egg cell itself. High rates of abnormal chromosome distribution are a major factor that can explain a lower rate of successful pregnancies in older women.

With this in mind, it seems reasonable to promptly evaluate women over 40 who are concerned about fertility. Before starting an evaluation, however, it is important to discuss with them some of the special considerations for the older woman trying to conceive. These would include general health issues, since women over 40 are more likely to have medical problems such as diabetes, hypertension, heart disease, all of which may complicate a pregnancy. Accordingly, older women contemplating pregnancy should have a thorough medical evaluation, including a mammogram. The increased incidence of genetic abnormalities in infants born to women over age 40 and the recommendation for prenatal chorionic villus sampling or amniocentesis should also be discussed with the patient prior to conception.

Expediting the Evaluation

Patients who are in their 20s or 30s and considering fertility treatment are often told to try unassisted conception for a year before in-depth fertility evaluations are conducted. In the case of women approaching 40, however, a basic infertility evaluation is indicated after only six months of trying to conceive.

Studies indicate that further delays in seeking diagnosis and treatment can seriously impair older women's chances of getting pregnant. Treatment may not always be necessary. But in cases where known or unknown infertility conditions exist and go untreated, passing time will only work against a woman's chances for pregnancy.

Ovarian Reserve: A Special Concern

Fertility evaluations for older women are comprised of the same tests and procedures as for younger women. Females are born with all the egg cells they'll ever have, so the older a woman is when she is trying to get pregnant, the more important is her egg supply. Testing of older women's ovarian reserve is crucial to diagnosis and determination of treatment options.

Ovarian reserve describes a woman’s reproductive potential with respect to egg quantity and quality. At present the best readily available way to measure ovarian reserve is a blood test drawn on the second or third day of the patient's menstrual cycle. The test measures the level of FSH (Follicle Stimulating Hormone) in the woman's blood. This measurement may be very important in choosing the optimal treatment for a patient and also to offer a realistic idea of her chance for a successful pregnancy.

Another test, the Clomiphene Challenge Test (CCT), can provide more information on ovarian reserve. CCT involves blood tests on specific days of the menstrual cycle, along with the administration of clomiphene citrate tablets.

Factors besides age that can negatively affect a woman's ovarian reserve include smoking, family history of early menopause, shortening menstrual cycle interval and previous ovarian surgery.