NEW YORK —  Donald Trump's (search) empire keeps on expanding, but his newest addition is on the home front.

Norma Foerderer, a Trump spokeswoman, confirmed a report Tuesday that the 59-year-old billionaire developer's wife, Melania Knauss (search), is pregnant.

"The baby is due in the spring," said Foerderer, adding that the child's gender is not yet known.

It would be the first child for the model and commercial actress, who lived with Trump for three years before they exchanged vows in January.

Knauss, 35, is Trump's third wife. He has four other children from his previous marriages: Donald Jr., 27, Ivanka, 23, and Eric, 21, with first wife Ivana Trump, and Tiffany, 11, with second wife Marla Maples.

Trump and his Slovenian-born bride were married in a lavish ceremony at Trump's newly unveiled $42 million Versailles-inspired ballroom at his Mar-a-Lago estate and club in Palm Beach, Fla.

The New York Post, which first reported the news about the pregnancy, said Knauss planned to spend time recuperating at Mar-a-Lago after giving birth.

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The mother-to-be has appeared in numerous print ads and graced the covers of Vogue and British GQ magazines. Trump's reality show "The Apprentice," entered its fourth season last week.