Blog by Dr Mary Birdsall

An IVF clinic in California has recently offered ‘would be’ parents a trait service, whereby they could choose to select embryos for hair, eye or skin colour. The clinic cannot change the DNA of the couple — if neither the mother nor the father has genes for green eyes, for example, then the clinic cannot give them a baby with green eyes.  Yet within the constraints inherent in the DNA of the couple, the IVF clinic is willing to screen embryos for these traits. So you could choose to have a baby with blue eyes, tanned skin and blonde hair.

This announcement has caused considerable controversy as there are concerns about the development of designer babies with further genetic screens selecting for intelligence or athletic prowess being on the horizon as we march towards a GATTICA world. TVNZ asked me to talk about designer babies on Breakfast TV, with the lovely Pippa who is 35 weeks into her second pregnancy (no trait screening required here). Click here to view the video.

In New Zealand we are allowed to screen embryos for genetic diseases such as cystic fibrosis, Huntington’s disease or haemophilia. The process of screening embryos involves a process known as pre implantation diagnosis (PGD). An embryo is cultured for 3 days until 8 cells have developed. A laser then creates a small opening in the outer shell of the embryo and one or 2 cells are removed and tested. The disease free embryos are then replaced into the uterus. I think this is an appropriate use of this technology but already boundaries are being tested, with couples requesting screening for skin diseases or various cancer genes.

The technology which I am looking forward to more, is when we can check whether an embryo has normal chromosomes prior to replacement. Currently a perfect looking embryo in a woman aged less than 36 has about a 50/50 chance of becoming a baby mostly due to chromosomal abnormalities. Sometimes more than 1 embryo is replaced in order to increase the chances of a pregnancy, with the trade off being the risk of multiple pregnancies. So the appeal for a blue eyed baby does not rate, I want a chromosomally normal embryo as a far better outcome.

Screening for sex selection is not permitted in New Zealand and jail sentences are a deterrent for kiwi IVF clinicians. PGD for sex selection is available in Asia and the USA with a considerable price tag attached. I do not think that New Zealand society is likely to allow sex selection in the foreseeable future.

I feel uncomfortable with PGD being used to screen for blue eyes or whatever other attribute is deemed desirable. The process of biopsying embryos reduces the chances of an embryo implanting into the uterus and forming a baby.

As a parent, I also love the genetic diversity that results from the combination of 2 people’s genes. Part of the miracle of being a parent is the discovery of what your child will look like.

So in summary, just because something is ‘do able’ does not mean we should be doing it and our focus should continue to be helping couples have healthy babies with unknown eye colours.