Since its introduction in the United States, assisted reproduction technology has helped allow women to conceive more than a million babies. However, with procedures such as in-vitro fertilization (IVF) has also come some concern -- many more multiple births often associated with complications. To address this issue, national guidelines recently recommended transferring fewer embryos per cycle as a means of curbing the rise in high-risk pregnancies. But, the question remained: would this sacrifice the overall success rate of IVF births? Now, researchers from Brigham and Women’s Hospital published in the April 15, 2004 issue of the New England Journal of Medicine, have shown that while the number of transferred embryos has declined, IVF results are actually improving in the United States.
It is estimated that infertility affects about 6.1 million people in the United States. Among this group, IVF accounts for about five percent of treatments. Since IVF has been offered in the United States, the rate of triplets and other higher order pregnancies rose by 423 percent (1980 through 1998). Studies have demonstrated that multiple pregnancies can be harmful for mothers and their children.
“Our study shows that IVF outcomes are clearly improving in the United States, possibly as a result of recommendations that encouraged physicians and patients to weigh the risks associated with multiple births and work together to lower the number of transferred embryos per cycle,” said Mark D. Hornstein, MD, senior author, and director, BWH’s Center for Reproductive Medicine. “The results demonstrate that infertility specialists in the United States are taking the initiative to lower multiple births. This is a responsible and encouraging development.”
In the BWH and Harvard Medical School study, Dr. Hornstein and his team compared national birth statistics with information from the CDC on IVF trends from 1995 to 2001. The data revealed that the average number of fresh-embryo transfers per cycle began decreasing in 1997, but the number of pregnancies and live births per cycle steadily increased. Although the rate of twins did not fluctuate, the percentage of pregnancies involving three or more fetuses decreased every year during the study period, with almost a 21 percent decline between 1998 and 1999, the year after the guidelines were released.
“I am excited and encouraged by these results,” said Tarun Jain, MD of BWH’s Division of Reproductive Endocrinology and Infertility and lead author of the study. “The trend toward improved practice patterns and outcomes leads us to believe that the American Society for Reproductive Medicine (ASRM) guidelines for embryo transfer were the right step to take and that we can make IVF a better treatment option for infertile families. Our study also suggests that the United States is acting responsibly by using professional self regulation of infertility clinics rather than pushing for legislation before there is proper time to collect and analyze the data.”