Aggregated News
Researchers looked at a database maintained by the Society for Assisted Reproductive Technologies (SART) and found the proportion of cycles that were begun but had no reported final outcome - successful or unsuccessful - increased from 2005 to 2010.
What's more, 13 U.S. fertility centers out of 341 accounted for half of those excluded cycles, and they reported significantly better overall pregnancy rates than the average clinic.
Researchers said some cycles may disappear from the data when clinics take frozen embryos from multiple rounds of fertility treatments and only implant the one that looks best - either as a treatment strategy, or to make their success rate look better.
That may be done most often with older women or others who have a lower chance of conceiving.
"Among this group of outlier clinics were very well known clinics, many of which are considered leaders in the field of ART in the United States," said Dr. Vitaly Kushnir, who led the study at New York's Center for Human Reproduction.
"Clearly, their pregnancy rates are significantly better than those of other clinics...
What's more, 13 U.S. fertility centers out of 341 accounted for half of those excluded cycles, and they reported significantly better overall pregnancy rates than the average clinic.
Researchers said some cycles may disappear from the data when clinics take frozen embryos from multiple rounds of fertility treatments and only implant the one that looks best - either as a treatment strategy, or to make their success rate look better.
That may be done most often with older women or others who have a lower chance of conceiving.
"Among this group of outlier clinics were very well known clinics, many of which are considered leaders in the field of ART in the United States," said Dr. Vitaly Kushnir, who led the study at New York's Center for Human Reproduction.
"Clearly, their pregnancy rates are significantly better than those of other clinics...