Kim, 33, and 36-year-old Kanye are planning a sibling for their nine-month-old daughter North West, reported Contactmusic.
"She wants to start trying by the end of the year, even though she hated being pregnant," a source said.
One of the major reasons of the couple wanting to have a second baby is to see that North gets a sibling close to her age.
"Kim has such a big family that she feels it's really important that there isn't a huge age gap between North and her siblings," the source said.
The couple will be tying the knot in Paris in the coming spring.