Patient and cycle characteristics predicting high pregnancy rates with single-embryo transfer: an analysis of the Society for Assisted Reproductive Technology outcomes between 2004 and 2013
Analysis of 2004–2013 Society for Assisted Reproductive Technology outcomes reveals a 10%–15% reduction in live birth rate and 47% reduction in multiple birth rate with single embryo transfer compared with double embryo transfer.
Volume 108, Issue 5, Pages 750–756
Authors:
Jennifer Mersereau, M.D., M.S.C.I., Jamie Stanhiser, M.D., Charles Coddington, M.D., Tiffany Jones, M.D., Barbara Luke, Sc.D., M.P.H., Morton B. Brown, Ph.D.
Abstract:
Objective
To analyze factors associated with high live birth rate and low multiple birth rate in fresh and frozen–thawed assisted reproductive technology (ART) cycles.
Design
Retrospective cohort analysis.
Setting
Not applicable.
Patient(s)
The study population included 181,523 women undergoing in vitro fertilization with autologous fresh first cycles, 27,033 with fresh first oocyte donor cycles, 37,658 with fresh second cycles, and 35,446 with frozen–thawed second cycles.
Intervention(s)
None.
Main Outcome Measure(s)
Live birth rate and multiple birth rate after single embryo transfer (SET) and double embryo transfer (DET) were measured, in addition to cycle characteristics.
Result(s)
In patients with favorable prognostic factors, including younger maternal age, transfer of a blastocyst, and additional embryos cryopreserved, the gain in the live birth rate from SET to DET was approximately 10%–15%; however, the multiple birth rate increased from approximately 2% to greater than 49% in both autologous and donor fresh and frozen–thawed transfer cycles.
Conclusion(s)
This study reports a 10%–15% reduction in live birth rate and a 47% decrement in multiple birth rate with SET compared with DET in the setting of favorable patient prognostic factors. Our findings present an opportunity to increase the rate of SET across the United States and thereby reduce the multiple birth rate and its associated poor perinatal outcomes with assisted reproductive technology pregnancies.
Comments
At the time of the freeze all it would be reasonable to transfer only one blastocyst especially in couples whose only a male factor infertility . Knowing that the stimulated cycle is generally less conducive to embryo implantation, it would be wiser to transfer nothing in the stimulated cycle and transfer only one blastocyst per spontaneous cycle after blastocysts vitrification. However, such a policy requires to be sure of the quality of its vitrification technique. Thus, in cumulative rate, the pregnancy rate would be significantly increased by one stimulation cycle.
The question is why the majority of clinicians continue, especially in Europe, to transfer embryos at day 2 of culture without any other rational that "it works" as well!
I therefore subscribe to the authors' thesis without reservation