For the most part, Barbie has kept her 39-18-33 measurements over the years. But her face has changed quite a bit. She may have had plastic surgery. That becomes a bit more clear when you look at the development of her face during her 56 years.
And you can see precisely that, thanks to the hard work of Tumblr blogger Forbidden Transmissions. She has lined up headshots of Barbie from every year during her long life. She comments:
Personally, I think the molds they used from 1987-1995 are the cutest, but I was still a little girl playing with Barbies at that time, so I may be a bit biased.
-via Nag on the Lake