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Just six months after giving birth to son Tristan Milos, Donald Trump Jr.'s wife Vanessa is pregnant again with the couple's fourth child.

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"Well, Vanessa & I have some good news," Trump Jr. wrote to his Twitter account this afternoon. "We are expecting baby num 4 in the fall!!!"

The new bundle of joy will make a little brother or sister to six-month-old Tristan Milos, Kai, 4, and Donald III, 3.

Vanessa and Donald tied the knot in 2005 at Trump Sr.'s Mar-a-Lago estate in Palm Beach, Florida.