Birth of a healthy girl after preimplantation gender determination using a combination of polymerase chain reaction and fluorescent in situ hybridization analysis

Objective: To perform preimplantation gender determination by a combination of polymerase chain reaction (PCR) sexing and fluorescent in situ hybridization technique using the directly labelled fluorescent alpha-satellite centromeric DNA probes for X and Y chromosomes. Setting: The IVF program of Illinois Masonic Medical Center. Patients: A couple requested preimplantation diagnosis because the mother is a carrier for hemophilia A. Results: Two blastomeres were aspirated from each of the four- to eight-cell embryos, and only the embryos with both fluorescent in situ hybridization and PCR results indicating female sex chromosomal 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 female only by PCR were followed up by confirmatory fluorescent in situ hybridization analysis demonstrating a discrepancy of PCR and fluorescent 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 embryo by a combination of PCR sexing and fluorescent in situ hybridization increases the reliability of preimplantation gender identification at the cleavage stage.