Kim Kardashian West has already prepared the nursery for her third child.

The 36-year-old reality star and her rapper husband Kanye West, 40, is said to have hired a surrogate to carry a baby for the couple, and it has been reported the pair have already prepared a special room in their Hidden Hills home for when the newcomer arrives next year, Us Weekly has reported.

Speaking about the 'Keeping Up With the Kardashians' star's preparation for the pending arrival, a source said: ''The nursery is already set up.''

But it is believed the raven-haired beauty and her spouse - who already have four-year-old daughter North and 21-month-old son Saint together - have yet to tell their brood they will be welcoming another child into the family because their oldest child likes to the centre of attention.

The insider explained: ''They probably won't bring it up until closer to term. Nori doesn't like sharing the attention.''

And the pair plan to keep details of the arrival as close to their chest as possible.

The source said: ''They won't announce anything until the baby is here.''

Although Kim and the 'Famous' rapper are keen to keep the news private, their other family members are ''so excited'' for the duo to welcome another little one into the family, and the Kardashian/Jenner gang.

The source said: ''Everyone in the family is so excited.''

It has also been reported a babysitter has already been recruited to work for the family and look after the tiny tot when she arrives, although Kim's family will also be on hand.

The source added: ''Kim has a great network of family who all want to spend as much time with the kids as possible. And they're so excited to have a third.''