Jones Institute scientists recommend blastocyst transfers for women who would have particular difficulty with a multiple pregnancy, Mayer said. Dr. Michael Soules, a professor at the University of Wash ington School of Medicine's department of obstetrics and gynecology and president of the ASRM, said his clinic only transfers blastocysts into women who are under 30 or who are using donor eggs from women of that age. Eggs from young women tend to be the most vibrant, so women in their 20s are at an especially high risk for multiple pregnancies, Soules said. Because of this, Soules will not transfer more than two embryos into a woman under 30. Blastocyst transfer has produced some surprising results.
Preliminary studies show that the procedure tends to yield more boys than girls.
The technology has another side effect.