Kim & Kanye Plan Another Baby: 4 Reasons Why Couples Use Surrogates
Kim Kardashian and Kanye West in 2015.
Credit: Mike Coppola/Getty

Celebrity couple Kim Kardashian and Kanye West have reportedly hired a surrogate to carry their third child. Although surrogacy is not very common, there are many reasons why couples may choose surrogates to be part of their fertility treatment.

Kardashian and West will reportedly pay the woman who will be their surrogate $45,000 over 10 months, and are required to pay a $68,850 deposit to the agency they used to find the surrogate, according to TMZ.

Kardashian, who is 36, has said she'd like to have a third child. However, during her last pregnancy, she had a condition called placenta accreta, which could make another pregnancy very dangerous. With placenta accreta, the placenta is not delivered from the woman's body shortly after birth (as it normally would be), which puts the woman at risk for severe bleeding.

"I want my kids to have siblings, but the doctors don't feel like it's safe for me," Kardashian said on a recent episode of her show "Keeping Up with the Kardashians." In another recent episode, she said she was considering surrogacy to have another child. "I think that I always knew that surrogacy was an option but I didn't think it was that realistic of an option…now I feel like that's my reality. I feel like surrogacy is really the only other option for me." [Keeping Up with the Kardashians' Health Problems]

Kardashian and West join others celebrities, including Jimmy Fallon and his wife Nancy, Sarah Jessica Parker and husband Matthew Broderick, and actress Nicole Kidman and husband Keith Urban, who have all worked with surrogates to carry their children.

A gestational carrier (or gestational surrogate) is a woman who carries a child for another couple, but the carrier is not the biological mother of the child, according to the American Society for Reproductive Medicine (ASRM). Instead, the egg from the biological mother and sperm from the father are combined in a lab dish (through a process called in vitro fertilization), before the fertilized embryo is implanted in the gestational carrier. (Couples who turn to a surrogate for carrying a pregnancy may use their own eggs and sperm, or donor cells.)

It is not very common for couples undergoing fertility treatment to work with a surrogate, said Dr. Tomer Singer, a reproductive endocrinologist at Lenox Hill Hospital in New York City, who spoke with Live Science about surrogacy in a 2015 interview. Singer estimated that about 5 percent of the couples he sees with fertility problems use a gestational carrier.

Some of the reasons why a couple may need to use a gestational carrier include:

  • The woman in the couple does not have a uterus. This can be because the woman was born without a uterus, or she needed her uterus removed to treat a medical condition such as cancer, Singer said.
  • The woman has a structural abnormality to her uterus, or has fibroids or scar tissue inside the uterus. These conditions can make it harder for a women to become pregnant or carry a pregnancy to term, Singer said.
  • The woman has a medical condition that would make pregnancy dangerous, as Kardashian does. Such conditions may include severe heart disease, severe kidney disease, severe diabetes, severe preeclampsia, or a history of breast cancer, according to ASRM.
  • The parents are gay men who use eggs from a donor along with a surrogate carrier to have a child.

Older women may be more likely than younger women to need a gestational carrier, because some the risk of some conditions that affect the ability to carry a pregnancy — such as uterine fibroids, and recurrent miscarriages — increase with age, Singer said. Older women may also be more likely to have chronic conditions that would make pregnancy risky, such as heart, lung or thyroid conditions.

Singer noted that laws regarding gestational carriers differ by state. Some states, such as California, allow gestational carriers to be paid, but other states do not allow compensation.

Editor's note: Portions of this article were previously published on LiveScience.

Original article on Live Science.