Kim Kardashian and Kanye West have plans to expand their family.
A source close to the couple tells ET that the parents of two have hired a surrogate to carry their third child. Kim has been very open about wanting to be pregnant again -- especially on Keeping Up With the Kardashians -- but being unable to do so because of health risks.
"It's something that has been in the works for a bit now," the source says of the surrogacy decision. "There was always a very high risk if Kim became pregnant with a third baby, so it was never really an option. They are excited to finally add to their family."
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Our source says Kim and Kanye have agreed to pay 10 monthly installments of $4,500 totaling $45,000. If there are multiple children, the surrogate will get $5,000 for each additional baby, and if the surrogate loses reproductive organs, she gets $4,000. Kim and Kanye are also required to deposit $68,850 with the agency.
Aside from refraining from smoking, drinking and drugs during the pregnancy, the surrogate also agrees to restrict sexual activities in the weeks leading up to the pregnancy, and also must not use hot tubs or saunas, handle or change cat litter, apply hair dye, drink more than one caffeinated beverage per day or eat raw fish.
The agreement provides that Kim and Kanye "assume the legal and parental responsibilities for any child ... that may possess any congenital or other abnormalities or defects."
TMZ was first to report the news.
Kim had notoriously difficult pregnancies with both her 4-year-old daughter, North, and her 1-year-old son, Saint.
"Last pregnancy, I had a condition called preeclampsia, which is a serious condition you can get during pregnancy," she explained in November 2015 on her blog about her experience giving birth to North. "It causes your body and face to swell, and that was very uncomfortable for me. I had early-onset preeclampsia and I had to deliver at 34 weeks, almost six weeks early."
"My placenta stayed attached inside my uterus, which is a condition called placenta accreta," Kim continued, revealing further serious complications she suffered after the delivery. "This is a high-risk condition that happens when the placenta grows too deeply into the uterine wall."
Kim, 36, suffered from placenta accreta again with the birth of Saint in December 2015.
Still, Kim once again expressed her desire to have another baby in March, though she had been advised against being pregnant by two doctors.
“I want my kids to have siblings, but the doctors don’t feel like it’s safe for me,” Kim explained to KUWTK cameras.
"Having more kids is definitely going to be a struggle," she acknowledged in another episode. "I've gone through so much with really bad deliveries that the doctors don't feel like it's safe again for me to conceive myself."
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Last month, both Kim's mother, Kris Jenner, and Kim's older sister, Kourtney Kardashian, offered to be Kim's surrogate during an episode of KUWTK.
-- Reporting by Jennifer Peros