Revised Guidelines Expanding Single Embryo Transfer Guidelines Result in Fewer Multiple Births at the Clinic Level and the National Level, Without a Decline in Live Birth Rates


Revised Guidelines Expanding Single Embryo Transfer Guidelines Result in Fewer Multiple Births at the Clinic Level and the National Level, Without a Decline in Live Birth Rates

Philadelphia, PA- Today, at the 75th Annual Scientific Congress and Expo of the American Society for Reproductive Medicine, researchers from the National Institute of Child Health and Human Development and Walter Reed National Military Medical Center presented results from a retrospective cohort study in which they compared Assisted Reproductive Technology outcomes in women under 38 years of age from the two years before and the two years after the 2017 revision of the ASRM/SART embryo transfer recommendations. The data showed a significant reduction in the number of embryos transferred and in twin pregnancy rates, but no reduction in over all live birth rates after the new recommendations were published and implemented.

In April 2017, ASRM/SART published revised embryo transfer guidelines limiting the transfer of two embryos to good prognosis patients under 38 only in cases where the patient had previously experienced several cycle failures.  The previous iteration of the guidelines had allowed the transfer of two embryos to patients in this category after the failure of one, initial, single embryo transfer (SET) cycle.

At Walter Reed it is clinic policy to transfer no more embryos than recommended by ASRM/SART guidelines.  The study analyzed data from cycles done during the two years prior to, and the two years after the guideline change. Patients included in the analysis were women under 38 years old, on their second embryo transfer cycle, using their own eggs, and not having preimplantation genetic testing. The main outcome measure was twin live birth.  There were 367 live births resulting from cycles done at the clinic during the study period.  Prior to the new guidelines, an average of 1.38 embryos were transferred per patient per cycle; this went down to 1.0 after the 2017 guidelines were implemented. The clinic’s twin pregnancy rate fell from 14.2% to 2.5%, with a corresponding reduction in the twin live birth rate from 12.5% to 2.5%. There were no higher order multiple pregnancies or births.  The percentage of transfers with good embryo quality increased (61% to 67%) over the time frame and overall live birth rate per transfer in this demographic was unchanged (47% vs. 50%) after the guideline revision.

In comparing SART’s nationwide ART cycle data, 2016 to 2017, the researchers found similar, though less dramatic, decreases in the rate of twins. These data included patients’ first cycles, as well as subsequent cycles. In 90,000 retrieval cycles in patients under 35, the twin rate decreased from 16.5% (2016) to13.3%(2017). And in 50,000 retrieval cycles in patients 35 to 37, the twin rate decreased from 15.6 to 12%.

ASRM Past President Christos Coutifaris, MD, PhD remarked, “This study shows that single embryo transfer works very well in this age range.  Despite some patients’ wish to have twins we must advise them that SET is safer and therefor more practical.  We are very pleased to see evidence that the embryo transfer recommendations are being implemented at a national level.”

P-99 Eubanks et al, “The Continued Push Towards Eliminating Twin Pregnancy: The Clinical Impact of the 2017 ASRM Embryo Transfer Guidelines” 

ASRM is a multidisciplinary organization dedicated to the advancement of the science and practice of reproductive medicine. The Society accomplishes its mission through the pursuit of excellence in education and research and through advocacy on behalf of patients, physicians, and affiliated health care providers. The Society is committed to facilitating and sponsoring educational activities for the lay public and continuing medical education activities for professionals who are engaged in the practice of and research in reproductive medicine.