BIRTH OF A HEALTHY GIRL AFTER PREIMPLANTATION GENDER DETERMINATION USING A COMBINATION OF POLYMERASE CHAIN-REACTION AND FLUORESCENT IN-SITUHYBRIDIZATION ANALYSIS

Objective: To perform preimplantation gender determination by a combin ation of polymerase chain reaction (PCR) sexing and fluorescent in sit u hybridization technique using the directly labelled fluorescent alph a-satellite centromeric DNA probes for X and Y chromosomes. Setting: T he IVF program of Illinois Masonic Medical Center. Patients: A couple requested preimplantation diagnosis because the mother is a carrier fo r hemophilia A. Results: Two blastomeres were aspirated from each of t he four- to eight-cell embryos, and only the embryos with both fluores cent in situ hybridization and PCR results indicating female sex chrom osomal complement were transferred, resulting in a singleton pregnancy and delivery of a healthy female infant, after prenatal confirmation of the diagnosis as female. The male embryos or embryos diagnosed as f emale only by PCR were followed up by confirmatory fluorescent in situ hybridization analysis demonstrating a discrepancy of PCR and fluores cent in situ hybridization results in four embryos, presumably because of a possible sperm contamination of the PCR reaction or chromosomal mosaicism. Conclusion: The analysis of two blastomeres from the same e mbryo by a combination of PCR sexing and fluorescent in situ hybridiza tion increases the reliability of preimplantation gender identificatio n at the cleavage stage.