Portman, who turned 30 last Thursday, announced in December that she was pregnant and planned to marry her boyfriend, French ballet dancer and choreographer Benjamin Millepied
The two worked together on "Black Swan
," in which Portman played a self-mutilating ballerina. She won the Academy Award for her performance in February.
The Israeli-born, New York-raised actress rose to fame playing the preteen protegee of a hitman in "The Professional," and appeared in the "Star Wars" reboots as Luke Skywalker and Princess Leia's mother. She was most recently in theaters with the romantic comedy "No Strings Attached."