Number of supernumerary vitrified blastocysts is positively correlated with implantation and live birth in single blastocyst embryo transfers

The number of supernumerary vitrified blastocysts correlates positively with the odds of implantation and live birth in single-blastocyst transfers.

Micah J. Hill, M.D., Kevin S. Richter, Ph.D., Ryan J. Heitmann, M.D., Terrance D. Lewis, M.D., Ph.D., Alan H. DeCherney, James R. Graham, M.S., Eric Widra, M.D., Michael J. Levy, M.D.

Volume 99, Issue 6, Pages 1631-1636, May 2013


To estimate if live birth in single blastocyst transfers is correlated with the number of sibling supernumerary vitrified blastocysts (embryos not transferred) generated from that same cycle.

Retrospective cohort study.

A large academic ART clinic.

All single-blastocyst transfers in 2010 graded as “good” embryos by Society for Assisted Reproductive Technologies (SART) criteria.


Main Outcome Measures:
Implantation and live birth.

Of the 655 single-blastocyst transfers that met inclusion criteria, implantation occurred in 65% and live birth in 54% of cycles. In chi-square analysis, patients with supernumerary vitrified blastocysts had a statistically higher implantation rate (65% versus 50%) and live-birth rate (56% versus 41%) when compared with patients without supernumerary blastocysts. Univariate logistic regression demonstrated an increase in implantation (OR 1.09; 95% CI, 1.03–1.15) and live birth (OR 1.06; 95% CI, 1.02–1.09) with increasing number of supernumerary blastocysts. Multivariate logistic regression analysis demonstrated that patient age and the number of supernumerary blastocysts were statistically significantly associated with implantation and live birth.

The number of supernumerary vitrified blastocyst correlated positively with the odds of implantation and live birth in good quality single blastocyst transfers. Patients with supernumerary blastocysts are good candidates for single embryo transfer.

  • Micah Hill

    We appreciate the opportunity to publish and discuss this manuscript. The presence of supernumerary embryos has been demonstrated to be a good prognostic factor for ART success. This paper furthered that knowledge by showing the number of supernumerary embryos correlates with outcomes, even when controlling for potential prognostic confounders. We hope this data will further encourage good prognosis patients with extra embryos to undergo single blastocyst transfer. We welcome any discussion or questions on this paper.

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