By Estil Strawn, MD
Recently an article in the New York Times described a woman’s complications of ovarian hyperstimulation syndrome (OHSS) following in vitro fertilization (IVF). The unfortunate complication that this woman experienced was a natural way for the article’s author to attempt to explore the types of medication regimens that are used in IVF.
To better understand what IVF clinics are attempting to accomplish, it is important to first understand what happens in nature. In nature, a woman’s body will usually only grow and eventually release one egg per month. Hopefully, this one egg is healthy, will encounter, and then be fertilized by one sperm per month. While the theory seems very simple, the reality is that it is extremely inefficient. In the best of circumstances, the likelihood of becoming pregnant naturally is between 15 to 20 percent in a given month. As each month passes, this percentage decreases. These percentages are based on the ideal age of a woman being less than 35 years and on her ability to be impregnated with reasonable numbers of healthy moving sperm. Women 35 years and older will have lower percentages of success.
In standard IVF, the general goal of most clinics is to have a woman use injectable fertility drugs that will hyperstimulate the ovaries enough so that anywhere from 10 to 15 high quality eggs will be retrieved. Of these 10 to 15 eggs, 50 to 70 percent will fertilize, leaving the patient with 5 to 11 embryos. Of these 5 to 11 embryos only half may be of good enough quality to ultimately lead to a delivered child. That is why IVF success rates for women under 35 years approach 50 percent, according to the Society for Assisted Reproductive Technology. IVF success rates begin to decrease dramatically after age 37.
During the IVF process, a woman’s ovaries are intentionally hyperstimulated. But fewer than 1 percent of women undergoing this process will actually have the unfortunate consequences described in the above New York Times article. (This is contrary to the very high figure that was quoted in that story.) This syndrome, which can be serious and even life threatening, is known as severe ovarian hyperstimulation syndrome. Certain patients appear to be at greater risk for this complication, primarily women with polycystic ovarian syndrome. The good news? With appropriate management of the IVF process, this complication is extremely rare.
As for the cost of traditional IVF, there is no debate that the traditional IVF process is expensive. Women over 37 or who have a history of poor response to these medications (fewer than 4 eggs retrieved with no more than 1 good embryo for replacement) will not only have to use more medication but also generally have much lower delivery rates than women under 35. Due to the expense of IVF in these “poor responders” and their continued poor likelihood of delivering a baby, “low dose or minimal IVF” protocols arose.
It is important for patients to understand that the goal of true “low dose or minimal IVF” protocols is to achieve between 1 to 3 eggs at the time of retrieval. Oftentimes the medications used in this process are common fertility drugs taken by mouth such as clomiphene citrate (Clomid). Similar to women who become pregnant naturally, delivery rates for “low dose or minimal IVF” for those with the best prognosis hover around 15 to 20 percent. This rate is lower than the rate seen with standard IVF. Therefore, the best prognosis patients frequently undergo multiple cycles of “low dose or minimal IVF”, increasing their cost. The situation is considerably more frustrating for the older patient or poor responder. While these patients may spend less money initially, if they fail to get pregnant and deliver a child, they may endure multiple attempts and potentially end up spending the same amount of money. Still, they may have no baby to show for their efforts.
On many levels, the terms “minimal stimulation and low dose” IVF have a tempting allure as patients seek solutions that appear more “natural”. Both patients and clinics will provide testimonials about their successes. However, review of the scientific evidence has failed to show improved (and often show lower) delivery rates compared to traditional IVF, particularly in women who are older or who are known poor responders. The primary advantage for these patients is the lower cost, which will allow them to continue to pursue their dream of having a biological child. So long as patients understand that these protocols are not superior to the standard or traditional approaches to IVF, patients will be making an informed decision.
Estil Y. Strawn, Jr. M.D. is doubly board certified in Reproductive Endocrinology and Infertility and Obstetrics and Gynecology. He is the medical director of the Froedtert and Medical College of Wisconsin Reproductive Medicine Center. Dr. Strawn is also full professor with tenure at the Medical College of Wisconsin where he serves as the director of the division of Reproductive Endocrinology and Infertility in the department of Obstetrics and Gynecology. Dr. Strawn blogs monthly with Attain Fertility.
Dr. Strawn has been helping patients overcome their fertility problems for 19 years, and has directed a center that is one of the largest providers of fertility services in the state of Wisconsin. This center provides some of the most advanced types of technologies in the country including pre implantation genetic diagnosis (PGD), egg freezing, egg and embryo donation, gestational carriers, as well as robotic surgery for uterine fibroids and reversal of fallopian tube sterilization.