Advanced Maternal Age

As more women choose to delay childbearing until their late 30s and early 40s, studies show that almost half of women older than 40 will experience infertility. Because female fertility usually decreases dramatically starting at age 35, 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 of conception. But the average 40-year-old woman has only a five percent per month chance for conception. Women over 40 who are concerned about fertility should be evaluated as soon as possible.

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 of 60 live births to 40-year-old women is genetically abnormal.

Though there are many possible explanations, 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.

Given these factors, women over 40 who are concerned about fertility should be evaluated as soon as possible. Before starting an evaluation, however, it is important to discuss 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. And the increased incidence of genetic abnormalities in infants born to women over age 40 means that older women who become pregnant should strongly consider amniocentesis, in which fluid in the sac surrounding the fetus is tested for problems, or chorionic villus sampling (CVS), in which tiny finger-like growths in the placenta are sampled and tested similarly.


Expediting the Evaluation

Fertility experts often counsel patients in their 20s or 30s to try unassisted conception for a year before proceeding to in-depth fertility evaluations. But for women approaching 40, a basic infertility evaluation is the best course 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. Of course, treatment may not always be necessary, but in cases where known or unknown infertility conditions exist and go untreated, passing time will work strongly against an older woman’s chances for pregnancy.


Ovarian Reserve: A Special Concern

Fertility evaluations for older women include 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, known as ovarian reserve. Testing of older women’s ovarian reserves is crucial to diagnosis and determination of treatment options.

Ovarian reserve describes a woman’s reproductive potential with respect to both 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 follicle stimulating hormone (FSH) in her 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 diminish a woman’s ovarian reserve include smoking, family history of early menopause, shortening menstrual cycle intervals and previous ovarian surgery.


Seeking Infertility Advice Over 40

The Reproductive Science Center of the Bay Area is a leading pioneer in infertility treatments including IVF with egg donation and LGBTQ family building. We’ll work with you to help you achieve your dreams of having a baby.

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