I'm trying to remember a story about a couple who have a designer baby.
The story is written in the first person as a series of letters or possibly e-mails from the baby's mother to a friend. It starts quite innocently with the mother saying how great it is that genetic diseases can be eliminated before birth. However, with subsequent letters it becomes clear that the baby is being treated as a pet or plaything rather than a human being. For example, the parents have the baby treated to retard growth so they can have a cute baby for longer rather than a stroppy two year old.
It's a horrifying story because the callousness of the parents only becomes apparent gradually. It's only towards the end you realise how appalling the situation is.
I read this in an anthology, and it was in the last thirty years. However I'm afraid I can't remember anything else about it. I was reminded of the story by the question A short story about baby on/off switch and it's possible it's the same story. However I don't remember anything about an on-off switch in the story I'm thinking of.