Comparison between fluorescent in-situ hybridisation and array comparative genomic hybridisation in preimplantation genetic diagnosis in translocation carriers

Objectives: To compare the pregnancy outcome of the fluorescent in-situ hybridisation and array comparative genomic hybridisation in preimplantation genetic diagnosis of translocation carriers.

Design: Historical cohort.

Setting: A teaching hospital in Hong Kong.

Patients: All preimplantation genetic diagnosis treatment cycles performed for translocation carriers from 2001 to 2013.

Results: Overall, 101 treatment cycles for preimplantation genetic diagnosis in translocation were included: 77 cycles for reciprocal translocation and 24 cycles for Robertsonian translocation. Fluorescent in-situ hybridisation and array comparative genomic hybridisation were used in 78 and 11 cycles, respectively. The ongoing pregnancy rate per initiated cycle after array comparative genomic hybridisation was significantly higher than that after fluorescent in-situ hybridisation in all translocation carriers (36.4% vs 9.0%; P=0.010). The miscarriage rate was comparable with both techniques. The testing method (array comparative genomic hybridisation or fluorescent in-situ hybridisation) was the only significant factor affecting the ongoing pregnancy rate after controlling for the women's age, type of translocation, and clinical information of the preimplantation genetic diagnosis cycles by logistic regression (odds ratio=1.875; P=0.023; 95% confidence interval, 1.090-3.226).

Conclusion: This local retrospective study confirmed that comparative genomic hybridisation is associated with significantly higher pregnancy rates versus fluorescent in-situ hybridisation in translocation carriers. Array comparative genomic hybridisation should be the technique of choice in preimplantation genetic diagnosis cycles in translocation carriers.