"[They] have one last embryo left," an insider told Us Weekly before going on to claim that the final embryo is male.
A second source is who added that the couple plan to have the embryo implanted in a surrogate "soon."
The couple had their youngest child, Chicago West, earlier this year by using this exact same method. Following Chicago's birth, Kardashian wrote about the experience and how they decided on that as their best option for growing their family.
"I have always been really honest about my struggles with pregnancy," she explained, according to Us Weekly. "Preeclampsia and placenta accreta are high-risk conditions, so when I wanted to have a third baby, doctors said that it wasn't safe for my — or the baby's — health to carry on my own."
"After exploring many options, Kanye and I decided to use a gestational carrier. Although I have used the term surrogate in the past, a gestational carrier is actually the technical term for a woman who carries a baby that she has no biological relationship to."
"A traditional surrogate donates her egg, is artificially inseminated with the father's sperm and then carries the baby to term," Kardashian added. "Since we implanted my fertilized egg in our gestational carrier, our baby is biologically mine and Kanye's."
"Having a gestational carrier is definitely different, but anyone who says or thinks it's the easy way out is completely wrong," she went on to admit. "People assume it's better because you don't have to deal with the physical changes, pain or complications with delivery, but for me it was so hard to not carry my own child, especially after I carried North and Saint."
"I'm so grateful for modern technology and that this is even possible. It's not for everyone, but I absolutely love my gestational carrier and this was the best experience I've ever had," Kardashian continued. "Our gestational carrier gave us the greatest gift one could give."
"The connection with our baby came instantly and it's as if she was with us the whole time," she concluded. "Having a gestational carrier was so special for us and she made our dreams of expanding our family come true. We are so excited to finally welcome home our baby girl."
At this time, there is no timeline on when the potential new Kardashian/West baby would be born but, at this point, it will likely not be in 2018.