Higher precentages of tubal - ectopic - pregnancy among women undergoing in vitro fertilization using frozen embryos were reported at the 2003 conference of the American Society for Reproductive Medicine.

Dr. David Keefe et al, from Brown University in Providence, RI, reported that 31% of the women who had IVF treatment using frozen embryos developed tubal or ectopic pregnancies. This was compared to 2 percent of women who underwent IVF with fresh embryos. This amounted to "nearly one-third of frozen embryo transfer pregnancies, 17 times more frequent than those seen with fresh IVF cycles."

The researchers were unable to give a reason for the increase, but they did say, "This study raises serious concerns and needs to be investigated." The Times in London (14Oct2003) suggested that there was evidence that freezing could alter the functioning of certain genes. [International Right to Life Federation Inc., vol 14, No 6, Nov/Dec 2003]