Objective: To evaluate the outcome of frozen-thawed ET using embryos previously biopsied for preimplantation genetic diagnosis during a fresh ET cycle.
Design: Prospective evaluation.
Setting: Assisted reproductive biology program.
Patient(s): A 31-year-old, G4, P1, TAB1, SAB2 carrier of a balanced RT 45,XX der(14;21)(q10;q10) translocation.
Intervention(s): Preimplantation genetic diagnosis by polar body biopsy. Excess embryos were frozen using the one-step method and then thawed.
Main outcome measure(s): Embryo survival after thawing and subsequent pregnancy outcome.
Result(s): Among the 32 mature oocytes, the results of fluorescence in situ hybridization were available for 25 polar bodies. Eleven were unbalanced, 10 were normal (8 fertilized), and 4 were balanced (3 fertilized) for the fresh IVF cycle. Two normal embryos were transferred. Four normal and 3 balanced embryos were cryopreserved. A chemical pregnancy resulted. Four months later, the 7 cryopreserved embryos were thawed; 2 survived (1 balanced and 1 normal) and were transferred. An ongoing pregnancy resulted, and a normal (46,XX) female was delivered.
Conclusion(s): Freezing and thawing of biopsied embryos resulted in a low survival rate. However, this should not be a deterrent to the cryopreservation of extra chromosomally normal embryos because the embryos that do survive are able to implant.