Astrid has been a Scandinavian royal name since the tenth century--and more recently in Belgium-- but has never really assimilated into our culture the way Ingrid did. Many people associated it with the Swedish author of the Pippi Longstocking stories, Astrid Lindgren.
With the renewed interest in ethnic names, Astrid might be worth consideration by parents with Norse roots, or who even have enjoyed a holiday among the fjords.
Astrid is the name of the teenaged heroine of the novel White Oleander and has appeared as a character in How to Train Your Dragon and the TV shows Fringe and Once.
Astrid is currently a Top 25 name in her native Sweden and, in 2013, reentered the US Top 1000.