Medical Marvels Going Too Overboard?

As I was reading A Brave New World, I found the advanced medical technology fascinating. I do not think that anyone can say that it is not amazing that doctors are able to pick and choose the outcomes of the physical characteristics for their baby or that doctors can keep the old young until the age of sixty (found in Chapter 7).
The more I thought about it, the more it made me realize how close we are to achieving such tasks in the world we live in today. If doctors today can produce the amount of skin necessary for a skin draft from a small amount of skin cells, create a functioning organ from stem cells, and even fully clone a sheep, then there is no telling what they will be able to do in a few more years or decades. This idea terrified me and intrigued me at the same time. If the technological advances from A Brave New World were to be achieved in reality, there is no doubt that many will be alleviated from the pain caused by old age and many other burdens, but at what price? Will we give up the things that make us human like actually being born or old age just for pleasure? Although I aspire to be a doctor, I do have to say that because of the possibility that such medical achievements can make us less human that there should be a limit to how far these achievements can go. What is your opinion on this? Can there a such a thing as too medically advanced?