In-vitro fertilization (IVF) is becoming more and more common, as older couples seek to have children bearing at least half of their own DNA. Sperm donors are a fairly easy and inexpensive solution for male infertility, and donor eggs are a virtual necessity for women over the age of 40 who want to give birth.
Using either one of these methods ensures that the baby will possess one of its parents' genes, but not both, giving rise to issues of identity and questions about when and how to inform the child about his or her unusual origins.
But with a continuing tendency for women to want to have children in advanced maternal age (over 35), or for same-sex couples to want children bearing at least one of their genes, one wonders how long this will continue to be abnormal.
Given that an IVF child possesses, by definition, at most 1/2 of his or her parents' genes, how much more compromising of "nature" would it be to make further alterations to an embryo's DNA via gene therapy? Given the option, many future parents, having already entered the realm of "unnatural" birthing, might be tempted to take advantage of whatever improvements to embryonic DNA technology can offer.
At what point is birth no longer "natural?"
Of course, the technology that would allow for such choices is still in the future.
But considering the enormous amount of gene-patenting underway, and the obvious applicability of biotechnology to controlling reproductive success, it seems more than likely that genetically-engineered IVF will be on the table for parents who can afford it, in the near future.
The question, then is: how many people would be appalled at the idea of further tampering with their future child's genetic quotient - and how many would leap at the opportunity?
Usually, once a technology becomers available, some people will use it, regardless of others' ethical questions. Once it becomes less expensive, more people will jump aboard. Eventually, its use acquires an inevitability that sweeps aside all such concerns.