Elective single embryo transfer trends and predictors of a good perinatal outcome United States 1999 to 2010

Elective single ET in the United States increased from 1999–2010. One-third of elective single ET among 35–37-year-olds resulted in a good perinatal outcome; transfer guidelines could be expanded.

Marissa L. Steinberg, B.A., Sheree Boulet, Dr.P.H., Dmitry Kissin, M.D., M.P.H., Lee Warner, Ph.D., M.P.H., Denise J. Jamieson, M.D., M.P.H.

Volume 99, Issue 7, Pages 1937-1943, June 2013


To assess trends in elective single 27 embryo transfer (eSET), and identify factors associated with a good perinatal outcome.

Retrospective cohort study.

Clinic-based data.

A total of 886,686 fresh, non-donor cycles reported to the National Assisted Reproductive Technology Surveillance System (NASS) during 1999–2010, of which 17,166 met criteria for eSET.


Main Outcome Measure(s):
Rates of eSET and good perinatal outcome (term, singleton infant with normal birth weight).

In 2010, eSET comprised 5.6% of all fresh transfers, representing an 8-fold increase since publication of first guidelines recommending eSET in 2004. Compared with other embryo transfers, eSET were nearly twice as likely to result in a good perinatal outcome (37.1% vs. 18.9%, respectively). Among women using eSET, those aged <35 and 35–37 had a good perinatal outcome (40.2% and 32.5%, respectively). In multivariable, log-binomial analyses, factors positively associated with a good perinatal outcome included: male factor infertility, day 5 embryo transfer, and having ≥3 supernumerary embryos for cryopreservation.

Between 1999 and 2010, national rates of eSET increased. Given the frequency of good perinatal outcomes among women aged 35–37, guidelines for eSET could be expanded to include patients in this age group with favorable prognoses.

  • Micah Hill

    I appreciated this data and the continued encouragement towards more eSET. Your data also was consistent with our publication last month, showing the number of supernumerary embryos is correlated with live birth in single blast transfers. I had 2 questions for you:

    1. Do you have the overall eSET rate from 2010 in blastocyst only transfers? Certainly the cleavage transfer data dilutes the overall eSET rate.

    2. An 8-fold increase in eSET is certainly a strong move in the right direction, although a 5.6% overall eSET rate still seems to fall far short of the mark. In your opinion, what is an ideal target percentage for eSET?

  • Fernando Bronet, PhD

    Very good news, an eightfold increase in elective single embryo transfer means a real trend in the proportion of SET, particularly if we take into account the high
    risk of multiple pregnancy and its associated adverse effects on mothers and
    children. Recently has been published a meta-analysis of perinatal outcomes
    according to the number of transferred embryo (Grady et al, 2012) and the
    authors found better results by using SET, I hope this trend will be a fact.

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