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1.
When one discovers their friend, who they didn't know was pregnant, just had a baby and posted it on Facebook.
Emily just had a Facebirth. I didn't even know she was pregnant.
by Max Simon Simmons Lovelace Ho August 06, 2013
 
2.
Constantly updating your facebook status to reflect your pregnancy, up to and including going into labour.
Ew, did you see Rhéa totally updating her facebirth?
by chet_woolery January 04, 2009