MICHIGAN STATE (US) — Multiple rounds of fertility treatments and the use of donor eggs can substantially improve a woman’s chances of having a baby, new research shows.
Published in the New England Journal of Medicine, the study of nearly 250,000 women shows that live birth rates approaching those of natural fertility are possible using assisted reproductive technology (ART) where eggs are removed from a woman’s ovaries, combined with sperm, and then returned to the woman’s body.
“This is good news for women who are trying to have a child,” says Barbara Luke, a researcher in the College of Human Medicine’s Department of Obstetrics, Gynecology, and Reproductive Biology at Michigan State University.
The number of ART treatments has more than doubled in the past 10 years, and live birth rates traditionally have been reported per cycle, or per one course of treatment.
While that is easily calculated and is the method used by national registries across the world, Luke’s team sought to estimate cumulative success rates with continued treatment.
“Women and families want to know the overall chances they will get pregnant, not necessarily whether they will get pregnant during a specific cycle,” she says.
Data were obtained from the Society for Assisted Reproductive Technology’s Clinic Outcome Reporting System for women undergoing treatment between 2004 and 2009. The system contains data on more than 90 percent of all clinics performing ART treatments in the United States.
The study of 246,740 women revealed 57 percent of women achieved a live birth via ART treatment, and 30 percent of all ART cycles resulted in a live birth. Success rates declined with increasing age for women using their own eggs, especially for those ages 38 years and older, but not for women using donor eggs.
The estimated natural fertility rate of the general population is about 20 percent per month, and estimated rates of conceiving spontaneously are 45 percent, 65 percent, and 85 percent after three, six, and 12 months, respectively.
The study looked at factors such as patient age, diagnosis, response to treatment, cryopreservation, and the stage at which embryos were transferred. Two major factors that influence ART success are favorable patient characteristics (specifically age) and good embryo quality. Among older women, live birth rates can be substantially improved with continued treatment and a change to donor eggs.
“Although the decision to use donor eggs is a very personal one, these analyses provide information regarding the likelihood of a live birth using this option,” says Luke.
These results also could guide regulations governing health insurance coverage for infertility treatment. The number of treatment cycles covered by insurance is typically limited to two or three.
The findings demonstrate that when using a woman’s own eggs, the success rates continue to rise beyond two to three cycles; additionally, the study may help providers and women decide when it is appropriate to change to donor eggs.
Researchers from the University of Michigan, Cornell Medical Center, Columbia University Medical Center, Dartmouth-Hitchcock Medical Center, Baylor College of Medicine, Redshift Technologies, and Spectrum Health Medical Group contributed to the study.
More news from Michigan State University: http://news.msu.edu/