“He’s here and he’s perfect!” Kardashian told her 60 million Twitter followers in a posting.
“He’s also Chicago’s twin lol I’m sure he will change a lot but now he looks just like her,” the reality star added.
Kardashian and her musician husband Kanye West have three other children – Chicago, a girl who was born in January 2018 also via a surrogate, son Saint, 3, and daughter North, 5.
The new baby’s name was not revealed.
Kardashian has said she decided to use a surrogate after doctors warned of serious health risks following the birth of Saint in 2015 if she became pregnant again.