New Horizons For PGD and PGS

Mr Stuart Lacey, Consultant Gynaecologist at Hammersmith Hospital has written about the latest developments in the field of preimplantation genetic analysis in the latest newsletter from the British Fertility Society.

“At the same time that scientific advances continue to progress, changes in regulation and service delivery are bringing this technology to an increasing number of patients. Although we are approaching the twentieth anniversary of the first PGD pregnancies, there are still a relatively small number of PGD cycles performed in the UK. Recent changes in legislation by the HFEA have resulted in the publication of a ‘list’ of conditions for which PGD is licensed. Applications are now available on-line, with the whole process being simplified and streamlined.

Previously PGD was delivered in the UK by IVF units in close collaboration with  a genetics service that was usually on site. This was in contrast to the United States where the PGD was performed in hub genetics clinics serving a satellite system of IVF units. This helped conquer the problems of geography and provided an economy of scale that resulted in more diagnosis being available to more patients within a shorter time-frame. Such units have now become established in the UK and there is a potential now for patients to be treated much closer to home , with their biopsied embryonic cells being couriered to the genetics centre for analysis, and the results emailed back to the local treatment team. Agreed standard operating procedures for counselling, consent and communication should lead to easier access and significant savings in time, cost and convenience.

Most cycles (in the past) have been performed using fluorescent in-situ hybridisation for up to 9 chromosomes analysed at either the polar body or blastomere stage. Current evidence has not shown any benefit to patients using this technique. Newer approaches analysing the entire chromosomal complement are currently under evaluation. Preliminary data is beginning to emerge but what is really needed is an adequately powered prospective randomised controlled trial.”