A recent study comparing the transfer of a single PGS-tested (pre-implantation genetic tested) embryo compared to the transfer of 2 untested embryos showed similar success rates but better baby outcomes for the group that underwent a single embryo transfer (a fresh transfer with up to 1 frozen transfer) with a PGS- tested embryo. The report was published in the American Journal of OB/GYN in February of 2014 by Richard Scott, MD.
In this study, the pregnancy rate for a single embryo transfer of a PGS-tested embryo was 69% (similar to success rates at RSC) and the pregnancy rates for a double embryo transfer of 2 untested embryos was 72% (also similar to RSC results).
However the percent of multiples births was much less when transferring only 1 embryo (1.6% versus 47%.) The twin pregnancies had a higher incidence of preterm birth and spent 5 times more days in the NICU as an infant.
This study confirms our own data at RSC showing baby outcomes are better by transferring one embryo at a time (if PGS tested) over 2 cycles, compared to transferring 2 embryos that are untested.
This is especially true for patients over 38 years of age. In our patient population that is under 38, we have very good outcomes by transferring one embryo at a time, even if NOT tested by PGS, and therefore do not always recommend doing PGS if a patient is less than 38 years of age.