The effect of aging on fertility

Abstract

In the developed world, deferment of marriage and postponement of child-bearing in marriage are resulting in unprecedented numbers of couples who desire pregnancy relatively late in life. These factors combine with a decline in fertility and an increase in pregnancy wastage with advancing age to present new challenges for the clinician treating infertility. Experience with young oocytes donated to older women indicates that the major responsibility for the decline in fertility with age can be attributed to aging oocytes. Oocyte donation offers new hope for infertile older woman, but important moral and social questions remain unanswered.

PIP: In the US reproduction has been increasing deferred as has marriage, and births to women aged 35-49 years are expected to increase to 8.6% in the year 2000. Decreased reproductive potential has been associated with the age and quality of the oocyte. Uterine aging can be compensated for by hormonal means, and oocyte quality can be compensated for with donations from young women. This possibility brings with it the ethical and social considerations of whether women over the age of 50 years should have children. A pregnancy rate of 30% per cycle can be achieved among women over 50 years with oocyte donors. The abortion rate increases with the age of the oocyte recipient from 14.0% among those aged 20-24 years to 44.5% among those aged 35 years and older. The risk of spontaneous abortion also was found to increase to about 75% for overall abortion and 26% for clinically recognized abortion among women over 40 years of age compared to only 12% among women aged less than 20 years. Use of fertility drugs also carries risks. In vitro fertilized pregnancy cases have provided sufficient evidence of reduced pregnancy with the advanced age of oocytes. When progesterone was given along with young oocyte donations, the achieved pregnancy rates were similar among women aged less than and more than 40 years of age. Among unassisted pregnancies, findings have shown a higher risk of obstetrical complications among older women; these outcomes could be minimized with good screening and modern obstetrical care. US vital data showed a doubling of the risk of infertility for women aged 35-44 years compared to women aged 30-34 years. Donor insemination programs have found it necessary to increase the number of cycles of treatment to 9-10 from the usual six among older women. The differences in cumulative conception rates between women aged more or less than 30 years of age was found to be statistically significant. The increased risk of ovarian cancer from superovulation was considered plausible.