IVF labs in the US market sex selection. Could it happen here?

Probably not. Nobody's doing it now and Bill C-13 will likely ban the practice

By Susan Orr-Mongeau

"Preimplantation genetic diagnosis (PGD) for sex selection and family balancing is not available here in Canada...not as far as I know," says Dr Cal Greene about the somewhat controversial genetic practice. Dr Greene is the medical director of the Calgary Foothills Fertility program and chair of the Canadian Fertility & Andrology Society (CFAS) Government Relations committee. He adds, "CFAS supports that aspect of Bill C-13 which would ban such activity, except for medical reasons." Many in Ottawa speculate Bill C-13, the proposed federal legislation on assisted reproduction, may make its way to the Senate sometime this session.

PGD is available in Canada but is only used to detect inherited diseases, select embryos that will be compatible for tissue donation to an ailing sibling, and to screen embryos that may carry a chromosomal abnormality, resulting in recurrent miscarriages. Most major in vitro fertilization (IVF) centres in Canada offer PGD procedures. "About 60% of the 30 or so procedures we did last year were for single gene defects," explains Jim Meriano, lab director at the START IVF centre in Toronto.

The PGD procedure involves microsurgery to remove one or two cells (blastomeres) from an embryo followed by an analysis of the genetic material contained in these cells.

All but one Canadian IVF centre offering PGD send single cell samples for analysis to an outside genetic lab in the US. That exception is the McGill University Reproductive Centre. The rest of the Canadian labs have to incur the cost of sending out the sample, which varies from $2,000 to $5,000 -- over and above the cost for the IVF treatment. Lab results are available within 24 hours so that embryos that are considered normal are then available for immediate transfer and implantation.

Dr Asangla Ao, scientific director of the PGD program at McGill, confirms that the university is currently the only Canadian IVF centre with on-site lab facilities capable of performing the gene amplification and diagnostic tests required to detect single gene defects. "We've performed PGD for single cell defects for both autosomal dominant and recessive disorders such as mytonic dystrophy, spinal muscular dystrophy, cystic fibrosis and beta thalassemia," says Dr Ao. The McGill lab performed about 50 PGD procedures last year.

Dr Ao emphasizes that PGD is a very promising procedure in the treatment of recurrent pregnancy loss. "If you look at the research on spontaneous abortions, the data indicates that about 50% are due to chromosomal abnormalities," she explains. Dr Ao adds, "identifying the need for this treatment before the patient hits advanced maternal age is an important factor in the successful treatment of infertility."

In all IVF patients the likelihood of success is greatly influenced by age. A low 7% live birth rate for mothers over 40 years old was reported by the CFAS in their most recent aggregate Canadian IVF clinical data from 2001. A higher chance of success was seen in IVF patients -- the live birth rate for those under age 35 was 30%.

The Genetic and Public Policy Center at Johns Hopkins University released a report on January 8 in which the safety and accuracy of PGD was discussed. The report notes that some find PGD morally unacceptable. There were also concerns of equity -- many can't afford it. The report goes on to raise broad ethical questions about the impact PGD has on family relationships, people living with disabilities and society as a whole. In Canada and as far back as 1997, the Tri-Council Code confirmed the importance of genetic research, while emphasizing the aim should be the advancement of knowledge and the amelioration of disease, not the improvement or enhancement of a population.

As the debate over its appropriate uses continues in Canada, PGD for sex selection and family balancing is already available at many clinics across the border. Newsweek magazine recently reported in their January 26 issue that this controversial practice is on the rise in the US.