Natalie, on Sunday won the Oscar for Best Actress for her stunning portrayal of a disturbed and obsessed dancer "Black Swan."
It is the first Oscar of Portman after being nominated twice. He earned his first nomination as supporting actress for "Closer" in 2004.
The actress, 29, who lost 9 kilos (20 pounds) in the preparation for the film directed by Darren Aronofsky, wore a purple triangle Descote appropriate for your pregnant figure.
In December, Portman said he hoped for a baby with fiance Benjamin Millepied, choreographer of "Black Swan." They met on the set of psychological drama, which is close to being a horror film.
Millepied helped him climb the stairs to the Kodak Theatre stage to accept his award. Portman called it "my beautiful love" who "has given me the most important role."
She was the favorite in its field, after razing honors this awards season. Portman won over Annette Bening, 52, nominated for an Oscar for the fourth time, three for best actress and for best supporting actress.
Speaking to reporters after receiving the prize, Portman said that the baby keeps feet on the ground amidst all the superficiality that can surround it.
"It feels like a protection against all the bells and whistles," he said.
When asked about the baby's reaction when he received the prize, Portman said he did not remember anything by the emotion but that he kicked during the musical numbers of the ceremony.
She said that in the near future hopes to stay at rest, without makeup and combing.
"And my baby is happy and healthy. What every parent wants," said the actress, who has said she does not know the sex of their child.
The other actresses were nominated alongside Portman Nicole Kidman, for "Rabbit Hole", Michelle Williams, "Blue Valentine", and Jennifer Lawrence, for "Winter's Bone."
