A reader of this blog recently requested that I explain why I utilize certain medications for my IVF/fertility patients and caution against the use of others. It all comes down to their effect upon egg quality. Although there is still much to be learned, most fertility specialists agree that what is going on hormonally in a woman’s body will impact the success of her cycle. That’s why I feel that it’s so important to optimize their hormone balance and individualize the protocol to suit each woman’s unique situation. Here’s what we know.
Prior to the month that an egg is going to have its opportunity to ovulate, the DNA within it remains inactive. It has been in this state of rest since birth. Whether or not egg develops in an environment that is balanced more toward estrogen or testosterone is the key factor which will determine whether it will mature normally. Eggs that are “estrogenized” are more likely to mature earlier, fertilize normally and develop into healthy embryos. “Androgenized” eggs are more likely to become atrophic, fertilize abnormally or become a first trimester miscarriage.
Typically, a woman’s fertility begins to drop dramatically about 13 years before she’s going to enter menopause; typically their mid to late thirties. This drop is associated with a shift toward a higher level of testosterone within the ovary and not surprisingly a drop in egg quality. What triggers this hormone shift within the ovary is that as women age they produce a more potent form of the hormone LH as well as develop a tendency to have greater sensitivity to this hormone. Therefore, when designing a protocol for a fertility treatment cycle, I feel it is important that we shift the balance toward a higher level of FSH relative to LH in order create a more favorable setting for egg maturation. Creating such protocols has been among the great accomplishments of my friends and colleagues Drs. Geoffrey Sher and Jeff Fisch when they demonstrated in their landmark paper that pregnancy rates can be substantially improved in women with a history of previous fertility treatment failure. The trick is to stimulate the ovaries with an FSH dominant signal early in their development and then add in a low level of LH late in maturation to optimize the quality of as many eggs as possible. From a practical standpoint, that means being able to control FSH and LH levels independently.
Many centers use simplified preparations of FSH and LH for their ease or lower cost. But I describe this as being similar to mixing your salt and pepper together in the same shaker. It may work in some situations but most patients need varying degrees of adjustment get “more salt” or “less pepper.” What makes this approach even more problematic is that these mixed preparations—called urinary derived gonadotropins—are made from the urine of the least fertile population, women in menopause. In effect, that “makes the pepper even spicier” as these women produce a far more potent form of LH. All too often, this results in a disappointing outcome. It is true that the lower cost, pre-combined products work well enough when given to the most fertile patients. I believe that’s what keeps the market for them alive. In addition to their impact upon egg quality however, I am also concerned about the impurities that they contain.
A recent analysis of both the standard and more highly purified urinary preparations found them to be 95 to 99% free of contamination. These contaminating proteins can not only impact the how a woman’s ovaries respond to them, they can also initiate an allergic reaction. Even more problematic, they carry a very low but real risk of transmitting infection which recently resulted in their use being banned in England and the rest of the United Kingdom.
In summary, the use of the latest technology has made it possible for companies to manufacture untainted FSH and LH in separate preparations so that their dosing can be uniquely adjusted to each patient’s individual needs. Better still, these are BioIdentical products that are exact replicas of the hormones produced by fertile women. Additionally, they are 100% pure and therefore free from the risk of allergic reaction or infection. For all of these reasons, I believe that these products are most suited toward meeting the needs of the patients that I see in my practice.