Predicting IVF Success Rates
A unique method is able to predict with 70% accuracy whether a second try at in vitro fertilization (IVF) will succeed. So say researchers from the Stanford University School of Medicine who have identified four factors that will determine whether a woman can become pregnant from a repeat IVF cycle. The author of the study is Dr. Mylene Yao, who is an assistant professor of obstetrics and gynecology at Stanford.
Yao says her team developed the tool in order to help physicians and their female patients decide whether a second IVF cycle would be worthwhile. The new prediction tool will also help researchers better understand the mechanisms of female factor infertility.
The women undergoing IVF treatment are given drugs that stimulate ovulation. Eggs are harvested from the woman's ovaries and then combined with a male partner's sperm in a culture dish. Physicians then apply various criteria to decide which of the embryos produced during a particular IVF cycle will be those most likely to bring about pregnancy and the subsequent delivery of a live baby. But until this time, the criteria have not been personalized by using details related to earlier IVF attempts.
The Society for Assisted Reproductive Technology says that IVF cycles using a woman's own eggs will result in pregnancy 18%-45% of the time. This is in part, dependent upon the woman's age along with several other variables.
Yao's team looked at the clinical data from 665 IVF cycles that were performed in 2005 at Stanford. The researchers checked the connection of each variable to the actual IVF outcome. The scientists found that the variables with true predictive powers of a successful outcome could be narrowed down to four factors: number of embryos, number of embryos containing eight-cells, percentage of embryos that ceased to continue division, and levels of FSH (follicle stimulating hormones). In regard to the latter two factors, embryos that cease to divide are destined to die while levels of FSH help to estimate a woman's ovarian function.
Yao says that this new, four-factor predictive tool has many implications for the woman who is trying to decide about whether to have a second go at IVF. For one thing, the first IVF test can now be thought of as a diagnostic test in addition to being a treatment procedure. Also, if the predictive tool bodes well for an individual woman, she may be encouraged to try again at least one more time. This time, the decision about IVF will be an informed one. Yao hopes to obtain FDA clearance for the brand new technology so it can be made available to all.