A new study out of Sweden is suggesting that women undergoing a second round of in-vitro fertilization cycles should get one embryo instead of two. The study says that one embryo has similar chance of getting implanted as the first round of the IVF treatment and also reduces the risk of multiple births.
The researchers examined the records of 661 women in the country who first underwent implantation with a fresh embryo, which was followed by implantation of one or two embryos if this attempt was successful. Women who were not able to get pregnant underwent subsequent cycles and were followed for up to 4 more tries.
The researcher report that 44% of those who got one embryo got pregnant and delivered live babies, while 51% of those who got two embryos did the same. However there were just 2.5% multiple births in the first group compared to 27.5% in the second.
Dr. William E. Gibbons, president of the American Society for Reproductive Medicine and a professor at Baylor College of Medicine in Houston said these findings should reassure women regarding the viability of the pregnancy if they receive just one embryo. "Since only a fraction of eggs released by a woman are capable of producing a baby, the pregnancy rate is higher when more than one embryo is put back in," he said.
The details of the study appear in the October 29 issue of the New England Journal of Medicine.