Image copyright Getty Images

Kim Kardashian and Kanye West have named their fourth child Psalm.

In a Twitter post with a picture of their new son, Kim wrote: "We are blessed beyond measure. We have everything we need."

Psalm or the book of Psalms appears in the old testament of the Bible and means "song".

The celebrity couple, who have been married for almost five years, already have three children called North, Saint and Chicago.

Just after the baby's birth by a surrogate Kim, 38, tweeted how perfect her new son was.

"He's also Chicago's twin lol I'm sure he will change a lot but now he looks just like her," Kim wrote.

During an appearance on Jimmy Kimmel Live in the US she was asked about baby names and said she had been googling Armenian boys' names but couldn't really find anything.

She then added: "I was truthfully thinking about just naming him Rob, my brother Rob, but then it's like, North, Saint, Chicago, Rob - it doesn't really go."

"Rob would have been a more normal name but all other three siblings have special names," naming expert Marc Hauser tells Radio 1 Newsbeat.

His thoughts on Psalm: [Huge pause] "It's short...but it's nice."

"The problem comes when it comes to mean something from the Bible. A first name shouldn't be a statement in religious terms," he adds.

The name Psalm is of Hebrew origin meaning a sacred song or hymn.

"In an international environment religion should be something private as it could have an adverse affect," Marc adds.

"You could meet anyone of any religion. If your name is Jesus or Muhammad - I'm not sure a religious statement should be the first statement you make."

Image copyright Getty Images Image caption "North is north for everyone, no matter what religion," says naming expert Marc Hauser

"I like North best. Geographical names are perfect. It's a good meaning, helps you navigate in your life and fits well with their surname.

"But Psalm doesn't feel such a perfect fit. It takes a lot of courage to invent a new name. They've made some good choices but perhaps not in this case."

They could've used Marc's services to invent a totally new name.

He charges £22,000 and spends up to eight weeks with a "team of international namers" checking in 12 most spoken languages.

Image copyright Marc Hauser Image caption Naming expert Marc thinks a religious first name could have an "adverse affect"

Religion has always been important to Kanye West's music.

Over the past year he's been making headlines for everything except his songs.

Tune into Kim Kardashian's Instagram Stories on Sundays and there you'll find Kanye and a choir belting out renditions of some of his most famous songs - as well as bits of music that seem to be brand new.

Known as Kanye West's Sunday Service, he recently appeared at Coachella alongside Chance the Rapper and Kid Cudi.

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