Kim Kardashian West thinks her newborn son is the ''most calm and chill'' of all of her children.

The 38-year-old reality TV star and her husband, rapper Kanye West, welcomed their fourth child into the world via a surrogate on Friday (10.05.19), and Kim has hailed her as-yet-unnamed son as the most peaceful of her children.

The brunette beauty - who also has kids North, five, Saint, three, and 15-month-old Chicago - wrote on Twitter: ''I was freaking out for nothing because he is the most calm and chill of all of my babies so far and everyone loves him so much. (sic)''

Meanwhile, a source recently claimed that Kim and Kanye, 41, already have a ''name in mind'' for their newborn child.

The loved-up couple haven't yet announced the tot's name, but according to a source, they already have some ideas.

The insider said: ''They have had a name in mind, but wanted to meet the baby before they decided.''

Both Kim and Kanye were present for their son's birth, and are said to be ''ecstatic'' about the new arrival.

The source added: ''Kim and Kanye were both present for the hospital birth on Thursday. They are ecstatic. Their little boy is super cute and looks like Kim.''

Kim announced the birth of her son on Twitter, and followed her message up moments later with another tweet claiming the newborn baby looks ''just like'' his sister Chicago.

The 'Keeping Up with the Kardashians' star wrote: ''He's here and he's perfect!

''He's also Chicago's twin lol I'm sure he will change a lot but now he looks just like her (sic)''