[Preimplantation genetic diagnosis of translocation].

OBJECTIVES

To observe the genetic characteristics of chromosomes and the rates of implantation and pregnancy in couples of translocation carriers who undergo preimplantation genetic diagnosis (PGD) and to evaluate the significance of PGD in the treatment of translocation carriers.

METHODS

Fluorescence in situ hybridization (FISH) was performed to analyze the embryos of 12 carriers of reciprocal translocation and 22 carriers of Robertsonian translocation. The results of diagnosis and the implantation and pregnancy rates were analyzed.

RESULTS

A total of 253 embryos from 36 couples were retrieved and FISH was applied for the examination. The characteristics of chromosomes were diagnosed in 225 embryos and the rate of successful PGD was 88.9%. Fifty-eight embryos were found to have normal chromosome or balanced translocation and were transferred into the uterus. The rate of implantation was 36% (5/14) and 14% (6/44) and the rate of pregnancy was 4/9 and 26% (5/19) for carriers of Robertsonian translocation and reciprocal translocation, respectively.

CONCLUSIONS

The FISH-based PGD is effective in the diagnosis of Robertsonian translocation and reciprocal translocation of embryos. It provides the possibility of a high rate of implantation and pregnancy, and avoids recurrent abortion and unwilling termination of pregnancy.