DNA is mostly locked up safely inside our cells, where it is used as an instruction manual to make every conceivable part of the human body. Cells are dying all the time, however, so we all end up with tiny amounts of free DNA floating in our blood. In a mother-to-be, this includes the DNA of her developing baby.
Today, laboratories routinely duplicate DNA and increase how much of it there is in a sample. The tiny amount of DNA in a mother’s blood suddenly hold incredibly powerful information, and arguably incredibly dangerous information.
By looking at the amount of DNA from particular chromosomes, we can now determine the child’s sex, and whether it has inherited any genetic disorders before the embryo even becomes big enough to be looked at with an ultrasound scan.
Prenatal screening with DNA isn’t particularly new – but using free DNA is. The advantage of this method is that it only needs a blood sample. Older methods involved taking a sample of the membrane or fluid around the embryo. These are significantly more dangerous, even carrying some risk of miscarriage.
If it can be determined what disorders an embryo may have before it is born, it may well be possible for the mother to decide whether to keep it – and if she does decide to keep it, everyone can be ready to treat the newborn. The concept of being able to anticipate the onset of a disease so early is a fantastic one – but it raises the inevitable ethical questions. Would it be right to get an abortion on the basis that the baby would be born with a disorder? I, personally, am of the opinion that the best definition for a foetus becoming a life is when it shows brain activity (around 12 weeks gestation). This, for me, represents the beginning of the conscious experience which we value as ‘human life’. Some religions tend to value conception as the start point, at times even putting emphasis on certain cells before conception.
Everyone from Aristotle to Johnny Rotten has had something to say about this. Biology does not fall into the clear-cut rules that human morality demands. Even birth is complicated… do you count the baby being outside? The baby being partially outside? The cutting or falling off of the umbilical cord?
We often neglect that, despite humanity’s obsession with deciding on beginnings and endings, life doesn’t work in that manner. Life has neither a single start point nor a single endpoint, because it forms from other life, and then forms other life. There has to be an overlap of parent and child – it’s not possible for a complex organism to just snap into existence. The jury will no doubt be out forever on the best point to choose as the beginning of the individual experience. The miraculous fact is that, despite all having experienced it, we will probably never know when we first start to feel.
Mentioned Today In ‘Headcandy’: