Experience of more than 100 preimplantation genetic diagnosis cycles for monogenetic diseases using whole genome amplification and linkage analysis in a single centre

Objective: To report the outcomes of more than 100 cycles of preimplantation genetic diagnosis for monogenetic diseases.

Design: Case series.

Setting: Tertiary assisted reproductive centre in Hong Kong, where patients needed to pay for the cost of preimplantation genetic diagnosis on top of standard in-vitro fertilisation charges.

Patients: Patients undergoing preimplantation genetic diagnosis for monogenetic diseases at the Centre of Assisted Reproduction and Embryology, Queen Mary Hospital-The University of Hong Kong between 1 August 2007 and 30 April 2014 were included.

Interventions: In-vitro fertilisation, intracytoplasmic sperm injection, embryo biopsy, and preimplantation genetic diagnosis.

Main outcome measures: Ongoing pregnancy rate and implantation rate.

Results: Overall, 124 cycles of preimplantation genetic diagnosis were initiated in 76 patients, 101 cycles proceeded to preimplantation genetic diagnosis, and 92 cycles had embryo transfer. The ongoing pregnancy rate was 28.2% per initiated cycle and 38.0% per embryo transfer, giving an implantation rate of 35.2%. There were 16 frozen-thawed embryo transfer cycles in which, following preimplantation genetic diagnosis, cryopreserved embryos were replaced resulting in an ongoing pregnancy rate of 37.5% and implantation rate of 30.0%. The cumulative ongoing pregnancy rate was 33.1%. The most frequent indication for preimplantation genetic diagnosis was thalassaemia, followed by neurodegenerative disorder and cancer predisposition. There was no misdiagnosis.

Conclusions: Preimplantation genetic diagnosis is a reliable method to prevent couples conceiving fetuses severely affected by known genetic disorders, with ongoing pregnancy and implantation rates similar to those for in-vitro fertilisation for routine infertility treatment.