Kim Kardashian West underwent five operations to "fix the damage" caused by pregnancy.
The 39-year-old beauty and her husband Kanye West used a surrogate for their two younger kids, Chicago, 23 months, and Saint, seven months, as she suffered from a number of complications while carrying North, six, and Saint, four, and doctors refused to help her get pregnant again.
Speaking in a video for her new SKIMS campaign, Kim said: "When I was pregnant with my daughter North, I had a condition called preeclampsia or toxemia, which is basically when the mom's organs start to shut down.
"The only way to get rid of that is to deliver the baby. At 34 and a half weeks, I had to go into emergency labour -- they induced me. North was four pounds. She was almost six weeks early."
She went on to explain that after delivering her daughter, her placenta never came out but grew inside her uterus.
She said: "That is what women die from in childbirth."
Despite the difficult pregnancy and labour, the couple wanted more children but the 'Keeping Up With the Kardashians' star had another complicated time while carrying Saint.
She continued: "After my daughter was born, I still continued to do the process of freezing my eggs. I was able to get pregnant through that with my son Saint, and then I had two embryos left. I had the same condition, same awful delivery that I had with my first daughter.
"After that, I had to have five different operations within a year and a half to fix the damage that all of that did on the inside."
Doctors refused to help Kim get pregnant for a third time.
She recalled: "I asked my doctors, 'Can I do it one more time?' And they were like, 'We won't even put an embryo in you -- that would be like malpractice.' "
Although she had a hard time having her family, Kim insists all the struggles were "worth it".
She concluded: "I'm so thankful for my beautiful kids, no matter how they came to me -- they came to me.
"I'm so thankful for surrogates. I'm really thankful for my family. I grew up with so many siblings. I just loved being in a big environment.
"I would have gone through the same pain and back for the result of having my babies. It was all worth it."