Kim Kardashian West spent a year deciding her surrogate.

The 'Keeping Up With the Kardashians' star is just days away from meeting her third child but she and her husband Kanye West, 40 - who also have four-year-old daughter North and two-year-old son Saint together - found it ''difficult'' to agree on the ''ideal'' woman to carry their baby but they are over the moon with their choice.

Speaking in the latest episode of her family's E! reality TV show 'Keeping Up With the Kardashians', Kim said: ''Getting a surrogate and finding someone that you really trust really is so much more for difficult of a situation than you could really imagine.

''You have to make sure that their lifestyle is healthy and they have to go through psychological testing, and it was maybe a year before we finalised our current situation. But I think everything happens for a reason, because the surrogate that I really loved got approved and she is such a nice person, like she's so easy to talk to and she's the perfect fit for us, but we have to decide quickly, are we really going to go through with this or are we gonna wait until we feel more prepared.''

The 36-year-old reality TV star was forced to go down the surrogate route after doctors warned her that there would be serious complications if she carried another baby.

She explained: ''It is frustrating like to not be able to do it on your own. It is a weird dynamic. I go to all the doctor's appointments and I try to be really present, but when you're not carrying it yourself it is such a fine balance of how much you're going to be in their lives. Of course, I want to know ever last detail that's going on with my baby and that's super frustrating, but I really trust my surrogate and I don't want to be that person that's trying to control her every move. It's going to be a long hard process but I'm going to take it one day at a time and hopefully it just gets easier.''

The couple - who got married in 2014 - have kept details of their surrogate under wraps but it's believed she's married and is the mother of two young boys.

The showbiz pair are said to have hired the woman for $45,000 through an agency.