Women should not delay trying to have a baby, thinking that as long as they are ovulating regularly, the biological clock can simply be put on hold or that they can simply freeze their eggs and then later decide if/when to thaw them for use. The truth is that as a woman progresses to and beyond her mid thirties, there is a steady and ever-accelerating decline in the quality of her eggs that will inevitably impact her chance of having a baby.

Not only will her chances decline over time, but so will the chance of a successful, healthy pregnancy. This is regardless of whether she tries to conceive without medical assistance, or following assisted reproduction (intrauterine insemination [IUI], in vitro fertilization [IVF] , or following egg freezing). You see….as a woman ages beyond her mid thirties, the chance of any ovulated or harvested egg being chromosomally normal declines, with the process accelerating rapidly as she advances to and beyond her 40’s. The result is a rapid reduction in conception rate and a rise in both miscarriages and chromosomal birth defects such as Down syndrome.

Consider the following statistics: at 30 years of age the natural conception rate per ovulation cycle is approximately 15-20%, the miscarriage rate…10-15% and the chance of a baby being affected by Down syndrome is 1:1000 . The comparable best case scenario following a woman of the same age undergoing IVF rates is a 50-60% conception rate, an unaltered (10-15%) miscarriage rate and 1:1000 chance of Down syndrome. Conversely, at age 45 years, the chance of natural conception per month of trying is probably 1- 2%, the chance of miscarriage 50-60% and the risk of a baby having Down syndrome is at least 1:40. Following conventional IVF, the same woman would have about a 3-5% chance of having a baby in an IVF center of excellence and, should she conceive, her risk of miscarrying would again be 50-60% and the risk of Down syndrome would again be 1:40. But using conventional IVF, this would be the best-case scenario. In fact, as recently reported from Australia, (this is probably similar for other 1st world counties too) where about 3 per cent of babies are born annually through IVF, one out of four cycles initiated in women 25-34 years of age resulted in a live birth, while at 45 years, only one out of 800 initiated IVF cycles resulted in a live birth (0.125%).

CGH EMBRYO/EGG SELECTION
Use of newer genetic tests such as comparative genomic hybridization (CGH) which analyzes all the chromosomes, thereby identifying “competent” embryos (i.e., those that are highly likely to propagate a viable pregnancy) so improves the efficiency of IVF that it can be considered to be a virtual “game changer”.  Not only does it vastly improve the baby rate per embryo transferred, but, regardless of the woman’s age, it dramatically reduces the risk of both miscarriages and chromosomal birth defects.

Who really benefits from CGH testing?  By allowing for thorough embryo evaluation, CGH offers major diagnostic and therapeutic advantages, especially in cases of “unexplained infertility“, recurrent IVF failure, repeated pregnancy loss (RPL) and in older women who not only produce fewer eggs per stimulated IVF cycle, but also whose eggs have a very much reduced chance of being chromosomally normal.

Embryo Banking in older women: It is especially in women over 40 years and those with diminished ovarian reserve that pre-implantation biopsy and selective banking (stock-piling) of CGH normal embryos over several cycles, that the real benefit of this advanced break-through technology can be realized. Such selective embryo storage, in essence diminishes the impact of a rapidly advancing biological clock, allowing such women to capitalize on whatever time is left…….as the saying goes, to “make hay while the sun shines.”

CGH and egg freezing: An egg is a single cell, and as such, no matter how good the freezing process, it is far more vulnerable to being damaged than is a multi-cellular embryo. Furthermore, even in young women, only about 1 in 3 eggs are chromosomally normal and this will inevitably steadily decline to less than 1 in 10 eggs by the time they reach their mid-40’s.  Combine the difficulty in safely freezing a single cell (egg) with the fact that chromosomally abnormal eggs cannot propagate a healthy baby, and you will readily understand why even today, the chance that a frozen egg will ultimately propagate a normal live baby is extremely low.

Given the adverse effect of advancing age on reproductive potential, women/couples seeking to initiate or expand their families should examine their reproductive options before reaching 35 years of age. These should include adopting a more aggressive stance such as moving actively and preferentially to assisted reproduction and IVF with fresh embryo transfer versus freezing their embryos or eggs.

In both cases, timing is everything, especially when it comes to conventional IVF where embryo selection is done using microscopic evaluation, and is thus much less exact than when CGH is used. And when it comes to the choice of egg freezing/banking, I would caution that without CGH egg selection, results are so poor and imprecise that this decision should be carefully deliberated.  I would venture to recommend that for women in their 40’s, egg freezing/banking might not be the best choice at all…with selective, CGH-based, embryo banking being a preferential approach.