Pregnancy, implantation, and live birth rates of blastocysts that were thawed, are warmed, biopsied, vitrified, and rewarmed for euploid blastocysts transfer

Abstract

Typically, blastocysts are biopsied (bx) and vitrified while awaiting preimplantation genetic screening (PGS) results. Sometimes blastocysts receive “no read” post PGS, leaving vitrified blastocysts with no genetic information. Furthermore, patients can desire PGS on previously frozen blastocysts which PGS was not performed. These scenarios require blastocysts to be warmed, bx'd, vitrified, and warmed again. The effect of double freezing and double warming on outcomes is unknown.