Lara and Eric Trump have welcomed a baby girl, Carolina Dorothy.
The president's son shared the news with his followers on Twitter late Monday.
"@LaraLeaTrump and I are excited to welcome Carolina Dorothy Trump into the world. We love you already!" he wrote.
On Tuesday, he shared of his family in hospital.
Ivanka Trump sent her younger brother and his family well wishes on Tuesday, tweeting, "We love you Lara, Eric, (big brother) Luke and sweet Carolina!"
Eric, 35, and Lara, 36, welcomed son Luke in September 2017. "Luke will be a great big brother!" Eric wrote when he shared news they were expecting again earlier this year.
The couple married in 2014. Lara formerly worked as a producer for Inside Edition but now works as an adviser to the president.
Carolina is President Trump's 10th grandchild. His oldest son, Donald Trump Jr., has five children with his ex-wife, Vanessa, and Ivanka has three children with her husband, Jared Kushner. Click here to see photos of his other grandchildren.