This is the seventh in a series of responses to common questions about Failed IVF Treatment.

There is little doubt that age is a very important determinant of IVF outcome.This is mainly because of the fact that a woman’s eggs undergo deterioration in quality as her age advances through and beyond her mid 30’s.Remember, eggs have been in the woman’s ovaries ever since she was incubating in her mother’s uterus.Thus, after a certain period of time – when she reaches her mid 30’s – a wear and tear effect increases the likelihood of chromosomal abnormalities that become unmasked with the maturation process.This maturation occurs with the LH surge that precedes normal ovulation or with the administration of hCG to induce ovulation.

In this regard, it is important to recognize that it is predominantly the egg (and not the sperm) that determines the chromosomal integrity (karyotype) of the embryo.An embryo with an irregular number of chromosomes (aneuploid) is incapable of propagating a normal baby.In fact, aneuploid eggs often fail to fertilize.Those that do either fail to divide normally or will implant defectively, resulting in an early pregnancy loss.In some cases the embryo might well attach and develop into a baby with a severe chromosomal abnormality.Such gestations often don’t survive until birth, but in some cases (such as with Down’s Syndrome) they survive through birth and beyond, albeit with a physical and/or mental handicap.

Here are a few general statistics that should help you understand the impact of age on embryo “competence” (the ability of the embryo to propagate a healthy pregnancy).Up until the early 30’s about 3 in 5 eggs and embryos (60%) are aneuploid.At 35-39 about 75-80% are aneuploid, and by age 40, 80-85% are chromosomally abnormal.By the mid 40’s, about 90% of eggs/embryos are aneuploid.To make matters worse, as the woman ages beyond 35, she gets ever closer to the menopause, and the number of eggs that become available for harvesting in IVF declines progressively.Thus, with a greater percentage of embryos being aneuploid (“incompetent”) and fewer embryos available, it should come as no surprise that IVF success rates decline progressively with advancing age beyond the mid 30’s, and then quite precipitously in the mid 40’s.

There is another point worth emphasizing and that is that an embryo that is numerically, chromosomally normal (euploid) has an excellent chance of propagating a viable pregnancy regardless of the age of the woman from whose ovary it was harvested.This means that the mechanism whereby advancing age progressively reduces the likelihood of a successful IVF pregnancy is the result of the declining potential in older woman to propagate euploid eggs rather than through progressive decline in the overall quality of all her eggs.

Aside from egg/embryo competency, there is also the fact that as women get older the incidence of reproductive disease such as uterine fibroids and adenomyosis also increase in frequency, and these can impact adversely on embryo implantation potential as well as the ability to achieve a full term delivery.

So, what can be done to offset some of the above inevitabilities?

First, it is important to counsel patients on the inevitable consequences of purposefully delaying treatment of infertility.I always counsel my older patients that the biological clock cannot be reset and that they should be both decisive and proactive when it comes to commencing IVF treatment.

Second, the protocol used for ovarian stimulation is also very important in the case of older women.This is because changes that take place in the ovary with advancing age render eggs much more vulnerable to Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) produced by the pituitary gland.Older women tend to experience a progressive overgrowth in the connective tissue surrounding their follicles (stroma or theca) that produce testosterone and other male hormones in response to LH.In addition, LH biologic activity increases with advancing age.Accordingly, there is a greater tendency for the older woman’s ovaries to produce excessive male hormones, which in turn can compromise egg development and increase the risk of egg/embryo aneuploidy.It is for this reason, in my opinion, that it is essential to avoid protocols of ovarian stimulation that will cause the woman’s ovaries to be overexposed to LH.That is why an individualized approach to ovarian stimulation is essential in older women (see a previous article posted on November 22 on this site).

Third, is the option of “embryo banking”.Here we attempt to arrest the biological clock by banking the older woman’s embryos over a number of consecutive cycles in order to increase the number of available embryos for transfer.Such embryo banking can be further embellished by testing each embryo for its chromosomal integrity using Comparative Genomic Hybridization (CGH) and then stockpiling the normal embryos for subsequent transfer to the woman’s uterus.

With this in mind, older women as well as those who (regardless of age) have diminishing ovarian reserve are in ever increasing numbers seeking access to SIRM’s embryo banking program in the hope of so extending their reproductive potential.

Finally, for those women for whom the biological clock has run out, there is always the option of donor eggs. In my experience, this is an outstanding option through which couples can still experience all of the joy and happiness associated with family.