| As CHR has developed special expertise in the management of diminished ovarian reserve (DOR), whether due to premature ovarian aging (POA) in younger women, or physiological aging of older women above age 40 years, we are seeing an ever increasing number of women with DOR requesting care. It is not surprising, therefore, that the resulting shift in patient population has led to a much more clnically challenging patient population. As we begin the second half of 2009, we decided to formally quantitate these changes for the first time.
Changing Ages: Older Women?
As Figure 1 nicely demonstrates, as recently as 2005/6, the average age of CHR patients reaching egg retrieval in an IVF cycle was ca. 36 years. Although it already represented a higher average age than other IVF centers reported at the time, by 2007/8, our average patient age had climbed even further to about 37.5 years. As of the first five months of 2009, the mean age of our IVF patients reached an incredible age of ca. 39.5 years.
Figure 2 shows more detail. Between 2005 and 2009, we noted a complete reversal of age distribution: in 2005, women under age 38 represented a large majority of patients, while by 2008, women above 39 years had come to represent the majority. In other words, CHR has been witnessing a very rapid “graying” of its patient population, likely to be unprecedented in any other IVF centers in the world.
Are We Seeing More DOR?
Since women of identical ages can have greatly varying levels of ovarian reserve (OR), age alone is not enough to understand the changing OR in our patient population. We, therefore, asked whether the levels of anti-Müllerian hormone (AMH), reflective of OR, changed in the same period.
Figure 3 clearly demonstrates that this, indeed, also has been the case. While AMH levels in women above age 36 remained the same or only minimally declined between 2006 and 2008, they very significantly declined in the youngest patient population at age 31 - 35 years.
All of this, of course, means that CHR’s population not only has been aging (i.e., “graying”) to a significant degree, but even young patients, seeking care at CHR, have dramatically changed recently, with an ever increasing number of them presenting with significant degrees of DOR and, therefore, POA. Demographics, thus, very clearly demonstrate a rather remarkable change in CHR’s patient population over the last few years, reflected by dramatically increasing ages and significantly declining OR. CHR’s patient population, therefore, is unmatched in poor prognostic indicators, which makes CHR’s pregnancy outcomes that much more noteworthy!
Comparing Patients among IVF Centers
Age and OR, of course, are the principal parameters, reflective and predictive of pregnancy chances. An IVF program’s overall performance will thus always depend on its patient population. We, approximately three years ago, demonstrated this fact when another well-known IVF center in the tri-state area allowed us to compare OR parameters between our patient population and theirs.
In those years, AMH was not yet widely used. Therefore, comparisons relied on follicle stimulating hormone (FSH) levels to assess OR. As Figure 4 well demonstrates, even then, CHR’s patient population demonstrated significantly higher FSH levels, reflecting much poorer OR.
What makes these findings, however, extra-remarkable is the fact that they predate the most recent increases in patient age and declines in OR in our younger patients, thus strongly suggesting that, if this same kind of comparisons were to be made today, the clinical difference in patient populations between CHR and other IVF centers would be even more pronounced than just a few years ago.
Outcome data
Because patient populations differ dramatically between individual IVF centers, it is difficult to compare pregnancy outcome data. Indeed, both publishers of annual IVF outcome data, the Centers for Disease Control (CDC) and the American Society for Assisted Reproduction (SART), very clearly point out this fact in their annual reports. Yet, it is understandable that patients still compare pregnancy outcome data between IVF centers since they really have no other way of judging the performance of IVF programs.
However, as the here presented CHR data very clearly demonstrate, when IVF pregnancy data are compared between centers, an educated consumer also tries to take into account the patient population that a given center treats. Our data, for example, very clearly demonstrate that women between ages 31 and 35 years changed dramatically between 2006 and 2008 (Figure 3). This would suggest that, as their OR on average declined, they became more “difficult” patients to treat and, therefore, their pregnancy chances should theoretically decline.
For similar reasons, CHR’s patients between ages 31 and 35 are likely to have poorer OR than women of identical ages at practically all other IVF centers in the country, if not the world, because we treat proportionally more women with DOR at those ages than virtually anybody else.
Moreover, it is telling that the statistical data in the CDC/SART annual center reports end with female age 42 years. This cut-off is obviously a reflection of the practice patterns at the vast majority of IVF centers, where women over 42 years are mostly refused treatment. In contrast, at CHR, we now routinely treat patients up to age 48 and our oldest IVF pregnancy, so far, has been established in a woman at age 46 years and 10 months.
This, of course, means that when we report pregnancy rates “above age 40,” they mean something very different from the pregnancy rates for the same age bracket at other centers, which rarely, if ever, treat women above age 42 years, unless they agree to egg donation.
To understand the implications of varying patient population is, therefore, of crucial importance when comparing the efficacy of IVF programs. We can state with considerable certainty, as reflected in the here reported demographic patient data, that no other IVF center in the world is likely to deal with as difficult a patient population as CHR. Given this adversity, it is remarkable that we have not only maintained our excellent pregnancy rates, but, in many aspects, continued to improve upon them.
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