FIRST PREGNANCIES AFTER PRECONCEPTION DIAGNOSIS OF TRANSLOCATIONS OF MATERNAL ORIGIN

Objective: To develop an approach to preimplantation diagnosis of tran slocations that would not require the use of specific DNA probes for e ach translocation type. Design: Retrospective analysis. Setting: Clini c. Patient(s): Two patients with 45XX,der(13;14)(q10;q10) karyotypes a nd one patient with a 46XX,t(4;14)(p15;q24) karyotype. Intervention(s) : Based on the observation that first polar body chromosomes remain at the metaphase stage for a few hours after oocyte retrieval, fluoresce nce in situ hybridization with chromosome-painting probes was used to perform preconception genetic diagnosis of translocation of maternal o rigin. Main Outcome Measure(s): Oocyte FISH analysis. Result(s): A tot al of 31 mature oocytes were produced, and results were obtained in 23 first polar bodies. After IVF-ET, all three patients became pregnant, preconception diagnoses being confirmed by prenatal diagnosis or birt h. Conclusion(s): Preconception diagnosis of translocations may reduce significantly the risk of chromosomally unbalanced offspring and preg nancy loss. This method is simpler than previous approaches because th e need to develop specific DNA probes for each translocation type is a voided. (C) 1998 by American Society for Reproductive Medicine.