In IVF Is Fresh or Frozen Embryo Transfer Better?
Although Louise Joy Brown, the first IVF baby, turned 40 years old this year, the science of IVF is still in its formative stages. Research questions continue to arise, and one current controversy is whether transferring a fresh versus a frozen-thawed embryo gives the better chance for a healthy baby. In a study of nearly 83,000 IVF patients recently published in Fertility and Sterility, there was no easy answer and the better technique may depend upon how many eggs and how many embryos are available.
Many IVF clinics have adopted a “Freeze All” policy for all embryos; however, according to this study from Duke University, freezing may be advantageous only for women who produce 15 or more eggs. Birth rates in these “high responder” patients were higher with frozen-thawed transfers, FET, (52%) vs. fresh transfers (48%). But women who do not produce as many eggs, that is, 14 or fewer, do better with fresh transfers than FET.
This study was large but did have a couple of limitations: the data were from the 2014-2015 SART Registry and practice patterns have continued to evolve since that time, and the study did not assess why patients opted for FET over fresh transfer.
More research is clearly indicated, but it may be stated with certainty that no two IVF patients are exactly alike, and each patient deserves a thoughtful, individualized treatment plan.
Kelly S. Acharya, Chaitanya R. Acharya, Katherine Bishop, Benjamin Harris, Douglas Raburn, Suheil J. Muasher. Freezing of all embryos in in vitro fertilization is beneficial in high responders, but not intermediate and low responders: an analysis of 82,935 cycles from the Society for Assisted Reproductive Technology registry. Fertility and Sterility, 2018 DOI: 10.1016/j.fertnstert.2018.05.024