Evaluating IVF Program Results
In 1989 Senator Ron Wyden introduced the in vitro fertilization (IVF) success bill requiring all IVF programs to report their results yearly to the CDC. Reporting to the CDC can be done through the Society of Assisted Reproductive Technology (SART) or the National ART Surveillance System (NASS). Reporting through the NASS is free, SART charges a fee of approximately $5,000 (Florida Institute for Reproductive Medicine (FIRM) reports through the NASS). The Wyden bill was intended to give couples meaningful data to make a treatment choice. While the bill was initially applauded there soon came the realization that programs were using the CDC statistics to promote their programs, i.e., programs were encouraged to transfer high numbers of embryos and not to treat poor prognostic patients. These practices produced better statistics, but also greater numbers of multiple pregnancies. Multiple pregnancies are associated with significantly increased maternal and fetal complications, some serious. From the CDC website the average number of embryos being transferred is documented as well as the multiple pregnancy rates. What cannot be determined from the data is patient selection. At the Florida Institute for Reproductive Medicine we tend to get a disproportionate number of patients who have failed other programs. We have a specific program designed to help the poor prognostic patient who feels very strongly about having their own genetic child – a highly discounted package of three IVF cycles.
With the improvement of embryo culture systems, most IVF programs have moved from transferring cleaved, day 2/3 embryos to blastocyst, day 5/6 embryos with resultant higher implantation/pregnancy rates. With the higher pregnancy rates the American Society of Reproductive Medicine as well as the Society of Assisted Reproductive Technology recommends transferring no more than two good quality blastocyst embryos to anyone and one embryo in good prognostic patients. This practice has all but eliminated triplet pregnancies. There is still, however a high incidence of twins.
Age 35 or less
Another major breakthrough in IVF has been the improvement in embryo freezing using vitrification as opposed to the slow freeze technique. With vitrification we have seen significantly increased embryo thaw/survival rates as well as ongoing pregnancy rates. Indeed pregnancy rates with vitrified blastocyst embryos mimic those for a fresh IVF cycle when estradiol levels are not significantly elevated. In high response patients pregnancy rates are significantly higher using vitrified embryos transferred in a cryo cycle where estradiol levels are near natures. In high response patients (high estradiol levels) fresh transfers have been shown to result in decreased pregnancy rates, decreased birth weights as well as a high incidence of ovarian hyperstimulation syndrome. For all these reasons, FIRM is cryopreserving blastocyst embryos using the vitrification technique and transferring all high response patients in cryo cycles.
Another exciting technology has been that of pre-embryo genetic screening (PGS), whereby blastocyst embryos are biopsied and tested for chromosomally normalcy. This technology does not harm the embryo and has resulted in higher pregnancy rates, lower miscarriage rates and the avoidance of chromosomally abnormal pregnancies. The FIRM is one of the few programs in the country that has its own in-house PGS program, making this technology more convenient and affordable. Almost 70% of our patients are choosing pre-embryo genetic screening.
At the FIRM the chance of pregnancy with the transfer of one blastocyst embryo for a female 35 years or less is approximately 40%, with two embryos 60%. With the transfer of two embryos almost 30-40% of pregnant patients will have a twin pregnancy. The chance of an embryo splitting resulting in identical twins is approximately 2-3%. With PGS pregnancy rates with a single chromosomally normal blastocyst is approximately 60%, with the transfer of two 80%. With the transfer of two PGS embryos the multiple pregnancy rate is approximately 50%. At the FIRM we strongly recommend transferring a single PGS embryo.
In order to evaluate a patient’s chance for pregnancy, therefore it is necessary to assess how many embryos (blastocysts) and the quality of embryos likely to be obtained. To estimate the number of embryos we need to estimate the number and quality of eggs (ovarian reserve). Ovarian reserve is best assessed by a blood test anti-mullerian hormone (AMH) as well as an ultrasound of the ovaries (antral follicle count). At FIRM we recommend most patients have an AMH and/or antral follicle count prior to IVF.
In summary, IVF best practices include:
- Transfer of blastocyst embryos as opposed to cleaved embryos
- Freezing blastocyst embryos using the vitrification technique as opposed to the slow freeze technique
- Transferring no more than two blast embryos, one in good prognostic patients
- Strong consideration of pre-embryo genetic screening
If a program is reporting inordinately high pregnancy rates it may well be due to transferring higher numbers of embryos and/or patient selection. We suggest looking at the experience and longevity of a program as perhaps the best assessment of quality. Experience and longevity take into account a program results, patient’s experience as well as costs. The Florida Institute for Reproductive Medicine is celebrating its 25th anniversary. The Institute has accounted for approximately 75% of all IVF pregnancies in the North Florida/South Georgia area. Our patients consistently rate us 5 stars on most internet review sites.